Coherent Verdi V-2, Verdi V-6, Verdi V-5 Operator's Manual

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Operator’s Manual Verdi™ V-2/V-5/V-6 Diode-Pumped Lasers

5100 Patrick Henry Drive Santa Clara, CA 95054

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

This document is copyrighted with all rights reserved. Under the copyright laws, this document may not be copied in whole or in part or reproduced in any other media without the express written permission of Coherent, Inc. Permitted copies must carry the same proprietary and copyright notices as were affixed to the original. This exception does not allow copies to be made for others, whether or not sold, but all the material purchased may be sold, given or loaned to another person. Under the law, copying includes translation into another language.

Coherent, the Coherent Logo, Verdi, and FAP-I are registered trademarks of Coherent, Inc.

This product is sold by Coherent pursuant to a limited sublicense under U.S. Patent No. Re 34,729. The rights which customers of Coherent receive through purchase of this product are restricted, and exclude any right to use the product in the telecommunications field.

Every effort has been made to ensure that the data given in this document is accurate. The information, figures, tables, specifications and schematics contained herein are subject to change without notice. Coherent makes no warranty or representation, either expressed or implied with respect to this document. In no event will Coherent be liable for any direct, indirect, special, incidental or consequential damages resulting from any defects in its documentation.

Technical Support

In the US:

Should you experience any difficulties with your laser or need any technical information, please visit our web site www.Coherent.com Additional support can be obtained by contacting our Technical Support Hotline at 800-367-7890 (408-764-4557 outside the U.S.) or E-mail [email protected]. Telephone coverage is available Monday through Friday (except U.S. holidays and company shutdowns).

If you call outside our office hours, your call will be taken by our answering system and will be returned when the office reopens.

If there are technical difficulties with your laser that cannot be resolved by support mechanisms outlined above, please E-mail or telephone Coherent Technical Support with a description of the problem and the corrective steps attempted. When communicating with our Technical Support Department, via the web or telephone, the model and Laser Head serial number of your laser system will be required by the Support Engineer responding to your request.

Outside the U.S.:

If you are located outside the U.S. visit our web site for technical assistance or contact, by phone, our local Service Representative. Representative phone numbers and addresses can be found on the Coherent web site, www.Coherent.com

Coherent provides telephone and web technical assistance as a service to its customers and assumes no liability thereby for any injury or damage that may occur contemporaneous with such services. These support services do not affect, under any circumstances, the terms of any warranty agreement between Coherent and the buyer. Operation of any Coherent laser with any of its interlocks defeated is always at the operator's own risk.

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TABLE OF CONTENTS

Preface .................................................................................................................................. ix

U.S. Export Control Laws Compliance ................................................................................ ix

Symbols Used in This Manual and on the Laser System .......................................................x

Section One: Laser Safety .......................................................................................... 1-1

Optical Safety ..................................................................................................................... 1-1

Safety Features and Compliance to Government Requirements ........................................ 1-2

Laser Classification.................................................................................................... 1-2

Protective Housing..................................................................................................... 1-3

Laser Radiation Emission Indicators ......................................................................... 1-3

Beam Attenuator ........................................................................................................ 1-3

Operating Controls..................................................................................................... 1-3

Location of Safety Labels .......................................................................................... 1-3

Electromagnetic Compatibility ........................................................................................... 1-3

Section Two: Description and Specifications.................................................. 2-1

System Description ............................................................................................................. 2-1

Laser Head ................................................................................................................. 2-2

Power Supply............................................................................................................. 2-3

Servo Loops ...................................................................................................... 2-3

Laser Diode Assembly...................................................................................... 2-4

Specifications...................................................................................................................... 2-5

Section Three: Installation......................................................................................... 3-1

Receiving and Inspection.................................................................................................... 3-1

Installation Kit .................................................................................................................... 3-1

Installing the Laser Head .................................................................................................... 3-1

Installing the Power Supply................................................................................................ 3-5

Final Installation and Initial Turn-On Procedures .............................................................. 3-6

External Interlock ............................................................................................................... 3-7

Dimensions ......................................................................................................................... 3-9

Section Four: Operation.............................................................................................. 4-1

Operation ............................................................................................................................ 4-1

Turn-on................................................................................................................................ 4-2

Turn-on (Cold-Start) .................................................................................................. 4-2

LBO Optimization (Optional Step)................................................................... 4-3

Daily Turn-on (Warm-Start) ...................................................................................... 4-3

LBO Optimization (Optional Step)................................................................... 4-4

Turn-off............................................................................................................................... 4-4

Turn-off (Daily Use) .................................................................................................. 4-4

Turn-off (Complete Shut-down)................................................................................ 4-5

Controls, Indicators, and Features ...................................................................................... 4-6

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Menu Displays .................................................................................................................. 4-12

System Status Messages .......................................................................................... 4-12

Fault Handling ......................................................................................................... 4-13

Low Power Warning ................................................................................................ 4-14

Section Five: External Computer Control....................................................... 5-1

How to Interface Verdi Lasers ............................................................................................ 5-1

RS-232 Command Language.............................................................................................. 5-1

Instruction Syntax for RS-232 Communication ........................................................ 5-1

ECHO Mode ..................................................................................................... 5-2

PROMPT Mode ................................................................................................ 5-2

?......................................................................................................................... 5-3

= or :.................................................................................................................. 5-3

RS-232 Interface Connection.............................................................................................. 5-3

RS-232 Port Configuration ........................................................................................ 5-3

Setting The Baud Rate ............................................................................................... 5-3

Instruction Set ..................................................................................................................... 5-4

Section Six: Maintenance and Service................................................................ 6-1

Troubleshooting .................................................................................................................. 6-1

FAP-I Replacement ........................................................................................................... 6-22

Preliminary Steps and Data...................................................................................... 6-22

FAP-I Handling Precautions .................................................................................... 6-23

Fiber Cable Handling Precautions ........................................................................... 6-24

FAP-I Removal ........................................................................................................ 6-25

FAP-I Installation ..................................................................................................... 6-27

Fiber Optic Cleaning......................................................................................................... 6-29

Equipment Needed................................................................................................... 6-30

Fiberscope......................................................................................................................... 6-30

Procedure ................................................................................................................. 6-30

Drop and Drag Procedure ............................................................................... 6-30

Cleanroom Swab Procedure............................................................................ 6-33

Alternative Cleaning Procedure...................................................................... 6-35

Examples of Good and Bad Fibers .......................................................................... 6-37

LBO Temperature Optimization ....................................................................................... 6-40

Performing the Optimization ................................................................................... 6-40

LBO Error Message ................................................................................................. 6-41

Fuse Replacement ............................................................................................................. 6-41

Battery Replacement......................................................................................................... 6-42

Preliminary Steps and Data...................................................................................... 6-42

Battery Removal and Installation ............................................................................ 6-43

Battery Charge Circuit Verification ......................................................................... 6-44

Verification of Successful Installation ..................................................................... 6-45

Cleaning the Air Filter ...................................................................................................... 6-45

Criteria for Cleaning ................................................................................................ 6-46

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Table of Contents

Section Seven: General Operating Principles................................................ 7-1

Laser Head .......................................................................................................................... 7-1

Gain Medium ...................................................................................................................... 7-2

Second Harmonic Generator............................................................................................... 7-2

Temperature Servos ............................................................................................................ 7-3

Output Optics...................................................................................................................... 7-4

Power Monitor .................................................................................................................... 7-4

Shutter................................................................................................................................. 7-4

Heat Sinking ....................................................................................................................... 7-5

Umbilical ............................................................................................................................ 7-5

Power Supply...................................................................................................................... 7-6

Laser Diode......................................................................................................................... 7-6

Battery Backup ................................................................................................................... 7-8

Cooling Issues..................................................................................................................... 7-8

Packing Procedure ......................................................................................................... A-1

Parts List ...............................................................................................................................B-1

Accessories ...........................................................................................................................C-1

Power Meters and Sensors..................................................................................................C-1

Recommendation .......................................................................................................C-1

Warranty .............................................................................................................................. D-1

Responsibilities of the Buyer............................................................................................. D-1

Limitations of Warranty ..................................................................................................... D-1

Glossary ..................................................................................................................... Glossary-1

Index ................................................................................................................................. Index-1

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

LIST OF ILLUSTRATIONS

1-1. Safety Features and Labels .............................................................................................. 1-4

2-1. Verdi V-2/V-5/V-6 Laser System ..................................................................................... 2-1

2-2. Laser Head Optical Schematic......................................................................................... 2-3

3-1. Installation Kit ................................................................................................................. 3-2

3-2. Riser/Heatsink.................................................................................................................. 3-4

3-3. Laser Head Base – Protective Cover Installed................................................................. 3-4

3-4. Laser Head Base – Protective Cover Removed ............................................................... 3-5

3-5. External Interlock ............................................................................................................ 3-7

3-6. Interconnect Diagram ...................................................................................................... 3-8

3-7. Laser Head Dimensions ................................................................................................... 3-9

3-8. Power Supply Dimensions............................................................................................. 3-10

4-1. Laser Head Features.........................................................................................................4-6

4-2. Power Supply Front Panel Controls and Indicators......................................................... 4-8

4-3. Power Supply Rear Panel Controls and Indicators........................................................ 4-10

4-4. Menus............................................................................................................................. 4-12

5-1. RS-232 Pin Configuration ............................................................................................... 5-4

6-1. Location of FAP-I Assemblies and Fiber Looping ........................................................ 6-23

6-2. Fiber Optic Covers and FAP-I Anode/Cathode Shorting Clip....................................... 6-24

6-3. FAP-I Assembly Interface.............................................................................................. 6-26

6-4. FAP-I Fiber Optic Connector......................................................................................... 6-27

6-5. Preparation of the Replacement FAP-I Assembly ......................................................... 6-28

6-6. Fiberscope with 20X Eyepiece and SMA Adapter........................................................ 6-31

6-7. Methanol Drop on Lens Tissue...................................................................................... 6-31

6-8. Placement of the Fiber Optic Against the Lens Tissue.................................................. 6-32

6-9. Movement of Fiber Optic Against Lens Tissue............................................................. 6-32

6-10. Methanol Residue .......................................................................................................... 6-33

6-11. Methanol Drop............................................................................................................... 6-34

6-12. Placement and Movement of the Swab Against the Fiber Optic Surface...................... 6-34

6-13. Folded Lens Tissue (Width Wise).................................................................................. 6-35

6-14. Folded Lens Tissue (Lengthwise).................................................................................. 6-35

6-15. Hemostat Attached to Properly Folded Lens Tissue...................................................... 6-36

6-16. Placement and Movement of the Folded Tissue Against the Fiber Optic Surface ........ 6-37

6-17. Good Fiber ..................................................................................................................... 6-38

6-18. Bad or Questionable Fibers............................................................................................ 6-38

6-19. Guidelines for Fiber Optic Inspection ........................................................................... 6-39

6-20. Power Supply Backup Battery....................................................................................... 6-43

6-21. Location of Battery Charge Circuit Resistor, R8........................................................... 6-45

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Table of Contents

A-1. Packed Verdi V-2/V-5/V-6 Laser Shipping Crate ........................................................... A-2

A-2. Top Foam for Verdi V-2/V-5/V-6 Laser Shipping Crate ................................................. A-3

A-3. Proper Packing of System Umbilical.............................................................................. A-3

A-4. Location of Packed Verdi V-2/V-5/V-6 Laser Maintenance Kit ..................................... A-4

LIST OF TABLES

2-1. Specifications................................................................................................................... 2-5

3-3. Laser System Dimensions................................................................................................ 3-7

3-1. Utility Requirements........................................................................................................3-8

3-2. Environmental Requirements .......................................................................................... 3-9

4-1. Operating States............................................................................................................... 4-1

4-2. Laser Head Features.........................................................................................................4-7

4-3. Power Supply Front Panel Controls and Indicators......................................................... 4-9

4-4. Power Supply Rear Panel Controls and Indicators........................................................ 4-11

4-5. Submenus....................................................................................................................... 4-14

5-1. Response from Laser after Receiving Instruction............................................................ 5-2

5-2. RS-232 Port Description.................................................................................................. 5-3

5-3. RS-232 Commands .......................................................................................................... 5-5

5-4. RS-232 Queries................................................................................................................ 5-6

6-1. Troubleshooting/Fault Messages ..................................................................................... 6-1

6-2. Battery Charge Circuit Voltages .................................................................................... 6-44

A-1. Verdi V-2/V-5/V-6 Laser Shipping Crate Contents......................................................... A-1

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

LIST OF CHARTS

1. Laser Does Not Start (No Light Output)............................................................................. 6-4

2. Laser Shuts Down (No Light Output)................................................................................. 6-6

3. Laser Output Unstable ........................................................................................................ 6-8

4. AC ON Indicator Does Not Light..................................................................................... 6-10

5. Head Laser Emission Lamp Fault..................................................................................... 6-12

6. External Interlock Fault .................................................................................................... 6-13

7. PS Interlock Fault ............................................................................................................. 6-14

8. LBO Temperature Fault; Vanadate Temperature Fault;

Etalon Temperature Fault; Diode 1 Temperature Fault .................................................... 6-15

9. Baseplate Temperature Fault............................................................................................. 6-16

10. Diode Heat Sink Temperature Fault ................................................................................. 6-17

11. Diode Over Current Fault; Over Current Fault; 10% Current Increase (No Fault).......... 6-18

12. Diode Under Voltage Fault; Diode Over Voltage Fault; Diode EEPROM Fault; LBO Not Locked at Set Temperature; Laser Head EEPROM Fault; Power Supply EEPROM Fault; Power Supply-Head Mismatch Fault; Shutter State Mismatch;

Head-Diode Mismatch Fault............................................................................................. 6-20

13. Battery Requires Service .................................................................................................. 6-21

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Preface

This manual contains user information for the Verdi™ V-2/V-5/V-6 Diode-Pumped Lasers.

Read this manual carefully before operating the laser for the first time. Special attention should be given to the material in Section One: Laser Safety, which describes the safety features built into the laser.

Use of controls or adjustments or performance of procedures other than those specified in this manual may result in hazardous radiation exposure.

Use of the system in a manner other than that described herein may impair the protection provided by the system.

U.S. Export Control Laws Compliance

It is the policy of Coherent to comply strictly with U.S. export control laws.

Export and re-export of lasers manufactured by Coherent are subject to U.S. Export Administration Regulations, which are administered by the Commerce Department. In addition, shipments of certain components are regulated by the State Department under the International Traffic in Arms Regulations.

The applicable restrictions vary depending on the specific product involved and its destination. In some cases, U.S. law requires that U.S. Government approval be obtained prior to resale, export or re-export of certain articles. When there is uncertainty about the obligations imposed by U.S. law, clarification should be obtained from Coherent or an appropriate U.S. Government agency.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Symbols Used in This Manual and on the Laser System

This symbol is intended to alert the operator to the presence of important operating and maintenance instructions.

This symbol is intended to alert the operator to the danger of exposure to hazardous visible and invisible laser radiation.

This symbol is intended to alert the operator to the presence of dangerous voltages within the product enclosure that may be of sufficient magnitude to constitute a risk of electric shock.

This symbol is intended to alert the operator to the danger of Electro-Static Discharge (ESD) susceptibility.

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SECTION ONE: LASER SAFETY

Laser Safety

Optical Safety

Laser light, because of its special properties, poses safety hazards not associated with light from conventional sources. The safe use of lasers requires that all laser users, and everyone near the laser system, are aware of the dangers involved. The safe use of the laser depends upon the user being familiar with the instrument and the properties of coherent, intense beams of light.

Direct eye contact with the output beam from the laser will cause serious damage and possible blindness.

The greatest concern when using a laser is eye safety. In addition to the main beam, there are often many smaller beams present at various angles near the laser system. These beams are formed by specular reflections of the main beam at polished surfaces such as lenses or beamsplitters. While weaker than the main beam, such beams may still be sufficiently intense to cause eye damage.

Laser beams are powerful enough to burn skin, clothing or paint. They can ignite volatile substances such as alcohol, gasoline, ether and other solvents, and can damage light-sensitive elements in video cameras, photomultipliers and photodiodes. The laser beam can ignite substances in its path, even at some distance. The beam may also cause damage if contacted indirectly from reflective surfaces. For these reasons, and others, the user is advised to follow the precautions below.

1. Observe all safety precautions in the preinstallation and operator’s manual.

2. Extreme caution should be exercised when using solvents in the area of the laser.

3. Limit access to the laser to qualified users who are familiar with laser safety practices and who are aware of the dangers involved.

4. Never look directly into the laser light source or at scattered laser light from any reflective surface. Never sight down the beam into the source.

5. Maintain experimental setups at low heights to prevent inadvertent beam-eye encounter at eye level.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

6. As a precaution against accidental exposure to the output beam or its reflection, those using the system should wear laser safety glasses as required by the wavelength being generated.

7. Avoid direct exposure to the laser light. The intensity of the beam can easily cause flesh burns or ignite clothing.

8. Use the laser in an enclosed room. Laser light will remain collimated over long distances and therefore presents a potential hazard if not confined.

9. Post warning signs in the area of the laser beam to alert those present.

10. Advise all those using the laser of these precautions. It is good practice to operate the laser in a room with controlled and restricted access.

Laser safety glasses can present a hazard as well as a benefit; while they protect the eye from potentially damaging exposure, they block light at the laser wavelengths, which prevents the operator from seeing the beam. Therefore, use extreme caution even when using safety glasses.

Safety Features and Compliance to Government Requirements

Laser Classification

The following features are incorporated into the instrument to conform to several government requirements. The applicable United States Government requirements are contained in 21 CFR, subchapter J, part II administered by the Center for Devices and Radiological Health (CDRH). The European Community requirements for product safety are specified in the Low Voltage Directive (LVD) (published in 73/23/EEC and amended in 93/68/EEC). The Low Voltage Directive requires that lasers comply with the standard EN 61010-1 “Safety Requirements For Electrical Equipment For Measurement, Control and Laboratory Use” and EN60825-1 “Radiation Safety of Laser Products”. Compliance of this laser with the (LVD) requirements is certified by the CE mark.

The governmental standards and requirements specify that the laser must be classified according to the output power or energy and the laser wavelength. The Verdi V-2/V-5/V-6 Lasers are classified as Class IV based on 21 CFR, subchapter J, part II, section 1040-10 (d). According to the European Community standards, Verdi V-2/V-5/V-6 lasers are classified as Class 4 based on EN 60825-1, clause 9. In this manual, the classification will be referred to as Class 4.

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Laser Safety

Protective Housing

Laser Radiation Emission Indicators

Beam Attenuator

Operating Controls

The laser head is enclosed in a protective housing that prevents human access to radiation in excess of the limits of Class I radiation as specified in the Federal Register, July 31, 1975, Part II, Section

1040.10 (f) (1) and Table 1-A/EN 60825-1, clause 4.2 except for the output beam, which is Class IV.

The appropriately labeled lights on both the power supply and the laser head illuminate approximately 30 seconds before laser emission can occur. Amber lights are used so that they will be seen when the proper type of safety glasses are used [CFR 1040.10(f)(5)/EN 60825-1, clause 4.6].

A beam attenuator, or shutter, prevents contact with laser radiation without the need to switch off the laser [CFR 1040.10 (f)(6)/EN 60825-1, clause 4.7].

The laser controls are positioned so that the operator is not exposed to laser emission while manipulating the controls [CFR

1040.10(f)(7)/EN 60825-1, clause 4.8].

Location of Safety Labels

Electromagnetic Compatibility

Refer to Figure 1-1 for a description and location of all safety labels. These include warning labels indicating removable or displaceable protective housings, apertures through which laser radiation is emitted and labels of certification and identification [CFR

1040.10(g), CFR 1040.2, and CFR 1010.3/ EN60825-1, Clause 5]].

The European requirements for Electromagnetic Compliance (EMC) are specified in the EMC Directive (published in 89/336/EEC).

Conformance (EMC) is achieved through compliance with the harmonized standards EN55011 (1991) for emission and ENC50082-1 (1992) for immunity.

The laser meets the emission requirements for Class B, group 1 as specified in EN55011 (1991).

Compliance of this laser with the (EMC) requirements is certified by the CE mark.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

LASER HEAD

REAR VIEW FRONT VIEW

TOP VIEW

POWER SUPPLY

Figure 1-1. Safety Features and Labels (Sheet 1 of 3)

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Laser Safety

Figure 1-1. Safety Features and Labels (Sheet 2 of 3)

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Figure 1-1. Safety Features and Labels (Sheet 3 of 3)

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Description and Specifications

SECTION TWO: DESCRIPTION AND SPECIFICATIONS

System Description

The Verdi V-2/V-5/V-6 laser system (Figure 2-1) is a compact solid-state diode-pumped, frequency-doubled Nd:Vanadate (Nd:YVO4) laser that provides single-frequency green (532 nm) output at power levels greater than 2 Watts/5 Watts/6 Watts. Single frequency operation results in lower noise in the green output.

The Verdi V-2/V-5/V-6 laser consists of the laser head and power supply connected by an umbilical. The umbilical contains a fiber optic cable to transmit light from the diode bar in the power supply to the laser head. It also houses electrical cables that provide control and monitoring signals between the laser head and power supply.

The laser head is shown mounted on a riser/heat sink. The riser/heat sink can be the passive version or the water cooled version depending on the operating environment.

LASER HEAD

RISER / HEAT SINK

UMBILICAL

Figure 2-1. Verdi V-2/V-5/V-6 Laser System

POWER SUPPLY

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

The passive riser/heat sink alone does not possess sufficient mass to maintain the laser head base below 55°C and accordingly should be mounted on a thermally conductive surface as described in the installation section.

Laser Head

The major optical elements are in a hermetically sealed head and includes:

• Vanadate as the gain medium

• LBO as the frequency doubling crystal

• An etalon as the single-frequency optic

• Optical diode

• Astigmatic compensator and three cavity mirrors

All optical components are mounted on proprietary Super Invar for strength and stability.

The temperature of the Vanadate and etalon are controlled by thermo-electric coolers (TECs), which are capable of heating or cooling the optical element. The temperature of the lithium triborate (doubling generator, or LBO), is controlled by a resistive heater. Accumulated heat in the laser head is dissipated by an optional riser/heat sink mounted on the laser head baseplate. Baseplate temperature is monitored by a CPU in the power supply, which will shut the system down if the laser head temperature reaches 55°C.

The laser head utilizes a Neodymium Vanadate (Nd:YVO4) crystal with the pump power provided by fiber delivery.

The nonlinear medium is a Type I, non-critically phase matched LBO crystal held at approximately 150°C. Unidirectional operation is achieved using an optical diode. Since the laser is a unidirectional, homogeneously broadened system, it tends to naturally run single frequency, with the etalon reinforcing this behavior.

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Description and Specifications

Power Supply

Nd:YVO

Pump

Astigmatic

Compensator

Etalon

Optical

Diode

Figure 2-2. Laser Head Optical Schematic

The main functions of the power supply include:

LBO

Green

Output

• Supplying DC power for the laser diode system that pumps the

gain medium in the laser head

• Controlling six servo loops

• Cooling for the laser diode assemblies

• Controlling and monitoring the laser output

• Storing data

• Providing a user interface.

Servo Loops The CPU controlled servo loops are briefly described below. See

“Temperature Servos” on page 7-3 for additional information.

Light loop – A photodiode in the laser head monitors the laser output. The CPU controls the output power from the Verdi laser based on the photodiode and in conjunction with the requested power from the power supply front panel. The CPU achieves this control by adjusting the diode pump power to the Vanadate.

• LBO temperature – The LBO doubling crystal is held at

approximately 148°C by a resistive heater. To prevent rapid change of temperature that may cause LBO crystal damage during warm-up, the CPU regulates a slow ramp-up to operating temperature. This typically lasts fewer than 30 minutes.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

In case of loss of AC power (due to a power failure or inadvertantly turning off the rear panel power switch), the laser is equipped with a battery powered, CPU-controlled, cool-down feature. This feature lowers the LBO temperature gradually to room temperature.

• Diode temperature – Diode operating temperature is held

constant by the TEC’s. Excess heat is dissipated by forced air cooling through heat sinks. The diode heat sinks are located within the power supply.

• Vanadate and etalon temperature – These optical components

are maintained at preset levels by TECs.

Laser Diode Assembly

One laser diode assembly is located in the power supply. This assembly is controlled and monitored by the CPU. The FAP-I™ (fiber array package- integrated) assembly houses a diode bar and a TEC.

See “Laser Diode” on page 7-6 for additional information on the laser diode assemblies.

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Description and Specifications

Specifications

Specifications for the Verdi V-2/V-5/V-6 lasers are listed in Table 2-1.

Table 2-1. Specifications

PARAMETER SPECIFICATION

Output Power 2, 5, or 6 W

Wavelength 532 nm

[5]

[1]

[3]

[2]

2.25 mm ± 10%

< 0.5 mrad

<1.1

±1%

< 0.02% rms

< 5 MHz rms

Beam Diameter

Beam Divergence

Power Stability

[4]

Noise

Polarization > 100:1, vertical, linear

Linewidth

Pointing Stability

All specifications are subject to change without notice.

[1] 1/e

[2] Full-angle divergence.

[3] Measured over 2 hours after a 15 minute warm-up.

[4] Measured from 10 Hz to 1 GHz.

[5] Measured over 50 msec with a thermally stabilized reference etalon.

[6] 25°C to 35°C temperature change.

at exit port.

[6]

<2 µrad/°C

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

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SECTION THREE: INSTALLATION

Installation

Receiving and Inspection

Installation Kit

Inspect shipping containers for signs of rough handling or damage. Indicate any such signs on the bill of lading. Report any damage immediately to the shipping carrier, and to Coherent Order Administration Department (800-438-6323) or to an authorized Coherent representative.

Retain shipping containers. The containers will be required if the system is returned to the factory for service. The containers may also be needed to support a shipping damage claim.

Coherent recommends that three people unpack and transport the Verdi V-2/V-5/V-6. The power supply weighs70 pounds and should be lifted by two people while the laser head, which weighs 22.2 pounds, can be lifted by the third person. The laser head and power supply are connected by the umbilical.

The installation kit contains the necessary hardware for Verdi installation. See Figure 3-1 for details.

Installing the Laser Head

The laser head is shipped with either a passive or a water-cooled riser/heat sink. This riser/heat sink maintains the Verdi output beam at a suitable height for pumping a laser such as the Coherent Mira.

A passive riser/heat sink when mounted on a thermally conductive surface (such as an optical table) provides sufficient heat dissipation for the laser head under normal ambient conditions. The temperature of the laser head baseplate is monitored by the Verdi power supply and can be displayed on the power supply front panel. Power dissipation through the baseplate is typically 20 to 25 Watts (30 Watts maximum). The Verdi will shut down if the baseplate temperature exceeds 55°C.

An optional water-cooled riser/heat sink is available for use with a chiller.

The laser head is shipped with a protective plastic plate installed over the baseplate. Leave the plastic plate in place until laser head is ready for installation.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

1. Riser/heat sink installation hardware

2. Operator’s manual

3. AC power cord

4. Power supply key

5. Installation kit case

6. Interlock-disassembled

7. Fuses and instructions

8. FAP-I installation hardware, including shorting clips, end caps, etc.

9. Laser head/heat sink mounting hardware

10. Dowel pins – laser head/heat sink

Figure 3-1. Installation Kit

1. Remove the packing material from the riser/heat sink (Figure 3-2).

2. Insert two dowel pins (Figure 3-1 , item 12) into the riser/heat sink dowel holes (Figure 3-2, item 1), ball-end up.

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Installation

Avoid damage to the laser head baseplate, which is milled to a flatness of ± 0.1 mm. This tolerance provides maximum thermal conduction between the baseplate and the mounting surface.

Keep the umbilical as straight as possible while avoiding rotating the laser head with respect to the power supply.

Do not apply thermal compound or any other material on the laser head baseplate or on the riser/heat sink.

3. Remove the laser head and power supply from the shipping crate. Place the laser head on its side and on a protected surface to avoid scratching the cover as shown on Figure 3-3. Remove the three screws (Figure 3-3, item 2) securing the protective plastic cover (item 4) to the laser head baseplate. Any scratches, damage, or contamination of the baseplate will reduce the thermal conduction between the baseplate and the mounting surface.

4. Refer to Figure 3-4 for the laser head dowel pin positions. Carefully place the laser head over the riser/heat sink and onto the dowel pins.

Do not use excessive force when clamping the Verdi to the riser/heat sink.

5. Use four laser head clamps (Figure 3-1 item 9) to secure the laser head to the riser/heat sink as shown in Figure 4-1 on page 4-6. Tighten the 4 clamps firmly using an Allen head wrench.

6. Proceed to the paragraph titled, “Installing the Power Supply”. The riser/heat sink clamps and chiller connection will be installed during the final installation procedures.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

1. Dowel holes (2)

2. Cooling water inlet and outlet (if included)

Figure 3-2. Riser/Heatsink

3. Laser head clamp screw holes (4)

4. Optical table clamp mounts (4)

1. Laser head

2. Protective plastic cover retaining screws (3)

Figure 3-3. Laser Head Base – Protective Cover Installed

3. Protective material

4. Protective plastic cover

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DOWEL PIN HOLES

Figure 3-4. Laser Head Base – Protective Cover Removed

Installation

Installing the Power Supply

1. Move the power supply to an accessible-friendly location, preferably away from heat producing sources. Ensure the cooling intake and exhaust (rear, top, and left side) are not blocked or obstructed.

If storing the power supply in a 19 in. (48 cm) equipment rack, allow a minimum horizontal clearance of 17.937 in. (45.56 cm) for the front panel of the power supply.

The system will not operate with the interlock open. For additional information on the interlock, including the connection of an external interlock circuit, refer to the paragraph titled, “External Interlock”.

2. Connect the interlock connector (Figure 3-1, item 6) on the rear of the power supply in the location shown in Figure 4-3 on page 4-10.

The interlock connector may be located in the installation kit or may be attached to the umbilical.

3. Connect the AC power cord on the rear of the power supply in the location shown in Figure 4-3 on page 4-10. Do not connect the AC power cord at this time.

Each customer must inspect the power cord and install the proper connector if necessary. The connector should be installed in a properly grounded outlet with a maximum of

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

10 Ampere service @ 110 V and 11 Ampere service @ 220 V for proper overcurrent and earth fault protection.

4. Proceed to the paragraph titled, “Final Installation and Initial Turn-On Procedures”.

Final Installation and Initial Turn-On Procedures

After installing the laser head and power supply in accordance with paragraphs titled, “Installing the Laser Head” and “Installing the Power Supply”, complete the installation as follows:

1. Position the power supply and laser head in the operating position with the umbilical as straight as possible. Ensure that the umbilical has a bend radius of 5 inches or greater. A distance of 6 to 24 inches is recommended between the Verdi output and any laser being pumped.

Excessively tight umbilical bends (less than a 5 inch radius) can cause permanent damage to the optical fiber.

2. If a water-cooled system is used, position the chiller in the operating position. Fill and prepare the chiller in accordance with the chiller user’s manual.

3. Cut the user-supplied cooling water lines to the appropriate lengths and use the water line hardware (Figure 3-1, item 9) to connect the riser/heat sink to the chiller (Figure 3-6). Apply teflon tape to the hardware threads and install the washers from the installation kit over the threads when connecting the stainless steel ferrule to the riser/heat sink. Check the system for leaks.

4. If a passive riser/heat sink will be used, ensure the riser/heat sink is mounted on a thermally conductive surface (such as an optical table) that provides sufficient heat dissipation to maintain the laser head baseplate below 55°C, preferably below 40°C.

5. Use four riser/heat sink clamps (Figure 3-1, item 1) to secure the system to the optical table as shown in Figure 4-1 on page 4-6. Tighten the two front clamps firmly using an Allen head wrench. Tighten the two rear clamps finger tight only.

6. Connect power supply to facility power. Ensure all packing materials have been removed.

7. Perform the procedure in paragraph titled, “Turn-on (Cold-Start)” on page 4-2.

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Installation

External Interlock

The system will not operate with the interlock open. An interlock connector is located on the power supply rear panel. The interlock status is monitored by the CPU. If the interlock is open, the message, “External Interlock Fault” will be displayed on the power supply front panel.

An external interlock circuit can be connected to the laser system and wired to a door switch to provide additional operating safety. When the door is opened, the laser will shut down. Press MENU EXIT key to clear the fault and continue operation.

To incorporate an external safety interlock circuit into the laser system, perform the following steps:

1. Turn off the laser system. Locate and remove the Interlock connector from the back of the Verdi power supply. This type of connector is called a “three pin mini-DIN”.

2. Slide the plastic cover off of the connector. Locate the two pins that have a wire soldered between them. These are pins 1 and

2. Remove the shorting wire and solder your interlock wires to these two pins. Make sure the wires have adequate strain relief.

3. Solder the other ends of the wires to an interlock switch. You can use many types of switches. The switch must be of a type that has its contacts closed when it is safe to operate the laser and open when it is not safe.

4. Figure 3-5 shows the wiring diagram for the switch. One wire runs from pin 1 of the connector to the normally open contact of the switch. The other wire runs from pin 2 to the common terminal of the switch. The switch is shown in the open position. This is the condition in which you do not want the laser beam to operate.

Figure 3-5. External Interlock

5. The interlock circuit in Verdi operates from a +/-12 VDC circuit. Its current is limited to around 1 mA. For these ratings, a “dry-circuit” type switch will give the most reliable operation.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

UMBILICAL

LASER HEAD

WATER LINES (if using Water Cooling)

AIR COOLED

POWER SUPPLY

FACILITY POWER

CHILLER

FACILITY POWER

Figure 3-6. Interconnect Diagram

Table 3-1. Utility Requirements

PARAMETER REQUIREMENT

Power Requirements 100 to 240 VAC

Maximum Current 6.5 Amps @ 100 VAC

7 Amps @ 220 VAC

Cooling:

Laser head:

Power supply:

Note: All specifications and requirements are subject to change without notice.

[1] The power supply is autoranging and will accommodate the full range of input voltages without hardware

changes.

[2] The electrical service should have a main power disconnect switch located in close proximity to the laser. The

main power disconnect switch shall be clearly marked as the disconnecting device for the laser, and shall be within easy reach of the operator.

[3] The passive riser/heat sink must be mounted on a conductive surface capable of maintaining the laser head base-

plate at less than 55°C. An optional riser/heat sink and chiller or chill plate can also be used. Refer to the paragraph titled, Installing the Laser Head, for additional information on removing waste heat from the laser head.

Riser/heat sink

Air-cooled with ambient air

[1][2]

[3]

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Table 3-2. Environmental Requirements

PARAMETER REQUIREMENT

Operating temperature 15 to 35°C (59 to 95°F)

Relative humidity 5 to 95% (non condensing)

Altitude Sea level to 10,000 feet

Installation

Dimensions

Figure 3-7. Laser Head Dimensions

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Figure 3-8. Power Supply Dimensions

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SECTION FOUR: OPERATION

Operation

Wear laser safety glasses to protect against the radiation generated from the laser. It is assumed that the operator has read Section One: Laser Safety, and is familiar with laser safety practices and the dangers involved. Ensure all personnel in the area are wearing laser safety glasses.

Table 4-1. Operating States

STATE SWITCH POSITION STATUS

Operation

OFF

STANDBY

• Power Switch (rear panel): OFF.

• All other switches: Any position.

• Power Switch (rear panel): ON.

• Keyswitch: STANDBY.

• Power Switch (rear panel): ON.

• Keyswitch: ON.

All functions off (except LBO CPU until cool-down is complete).

Laser diode off.

Vanadate temperature servo on.

LBO temperature servo on.

Etalon temperature servo on.

Laser diode on.

Vanadate temperature servo on.

LBO temperature servo on.

Etalon temperature servo on.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Turn-on

Ensure the keyswitch is in the STANDBY position prior to performing the “Cold Start” Turn-on procedure. Turning the keyswitch to the ON position will result with the fault “LBO Not Locked at Set Temp” displayed until the LBO reaches operational temperature.

Turn-on (Cold-Start)

The cold-start procedure should be used when the Verdi V-2/V-5/V-6 power supply rear panel power switch has been off for longer than 30 minutes (laser in the OFF state as described in Table 4-1). In this condition, all servos are off and the Verdi has to stabilize the servos which can take up to 30 minutes. During this time, the laser diode cannot be turned on.

See the paragraph titled, “Second Harmonic Generator” on page 7-2 for additional information on the LBO heater ramp-up and stabilization.

Cold-start can also be accomplished when the laser is externally controlled by a computer. Refer to Table 5-3 on page 5-5 and Table 5-4 on page 5-6 for a list of RS-232 commands and queries.

Use the following procedure to perform a cold-start of the system.

1. Ensure the keyswitch is in the STANDBY position.

2. Set the power switch on the power supply rear panel to “on.” The AC power and LASER EMISSION indicators will light. (See Table 6-1 on page 6-1 if an indicator does not light.) The power supply display will then indicate “System warming up”. Refer to Figure 4-4 on page 4-12 for the front panel displays

and menus

3. Turn on the chiller. Verify there are no cooling line connection leaks at the Verdi riser/heat sink, and at the chiller.

4. Verify the chiller water temperature is set to approximately 20°C. Adjust the temperature setpoint as required.

5. Set the output power to the desired level using the POWER ADJUST knob. The output power can be adjusted to 0.01 watts to facilitate beam alignment.

1. Although the Verdi laser system will display zero operating hours, please note that the system was turned on and operated as part of our thorough manufacturing and final test procedures.

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Operation

6. Allow 30 minutes for the heaters and thermo-electric coolers (TECs) to achieve operating temperature. The status of all servos can be viewed by scrolling to the Servo Status screen.

Once this process is complete, the display will indicate “Standby”. The system is now ready for key on.

Ensure the laser output is blocked or directed at an intended target. Ensure all personnel in the area are wearing laser safety glasses.

7. Open the shutter by pressing the SHUTTER OPEN pushbutton on the power supply front panel.

8. Laser light will emit from the laser head after the current ramp-up.

Coherent strongly recommends a weekly log book of diode current (read from front screen) vs. output power level is maintained. Such a record would prove to be very useful in troubleshooting.

LBO Optimization (Optional Step)

Daily Turn-on (Warm-Start)

If diode current increases 10% or more over the initial installation value (or current baseline value) to achieve the same output power, use the LBO Optimization menu shown in Table 4-5 on page 4-14 to access the LBO optimization routine. See the paragraph titled, “LBO Temperature Optimization” on page 6-40 for details on the LBO optimization procedure.

A warm-start can be performed when the Verdi power supply rear panel power switch has been on for more than 30 minutes (laser in standby as described in Table 4-1).

The recommended daily operation of the Verdi is to use this warm-start turn-on procedure in conjunction with the turn-off procedure that leaves the rear panel power switch in the “on” state.

If the power supply has been off for longer than 30 minutes (AC ON indicator not lit), perform the procedure in paragraph titled, “Turn-on (Cold-Start)”.

Warm-start can also be performed when the laser is externally controlled by a computer. Refer to Table 5-3 on page 5-5 and Table 5-4 on page 5-6 for a list of RS-232 commands and queries.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Use the following procedure to perform a warm-start of the system.

1. Verify there are no cooling line leaks at the Verdi riser/heat sink and at the chiller. Verify the chiller water temperature is set to 20°C. Adjust the setpoint temperature as required.

2. The LASER EMISSION indicator should be on. If the indicator is not on, refer to Table 6-1 on page 6-1. Turn the keyswitch on the power supply front panel to ON.

3. Once the keyswitch is in the ON position, the Main Display will appear on the power supply front panel display. Refer to Figure 4-4 on page 4-12 for a list of the display menus.

Ensure the laser output is blocked or is directed at an intended target. Ensure all personnel in the area are wearing laser safety glasses.

LBO Optimization (Optional Step)

Turn-off

4. Laser light will emit from the laser head after current ramp-up.

5. Open the shutter by pressing the SHUTTER OPEN pushbutton on the power supply front panel.

6. If necessary, adjust the POWER ADJUST knob for the desired output power level. The output power can be adjusted to

0.01 watts to facilitate beam alignment.

Coherent strongly recommends a weekly log book of diode current (read from front screen) vs. output power level is maintained. Such a record would prove to be very useful in troubleshooting.

Turn-off (Daily Use)

When the Verdi is being used on a daily basis, turn-off consists of turning the keyswitch to the STANDBY position. This shuts off the laser diodes and places the Verdi in standby as described in Table 4-1 on page 4-1. This method avoids the heater ramp-up cycle described above in the paragraph titled, “Turn-on (Cold-Start)”.

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Operation

Do not turn the power switch on the power supply rear panel to the OFF position. If all power is to be removed from the system, perform the procedure in paragraph titled, “Turn-off (Complete Shut-down)”.

Turn-off daily use can also be performed when the laser is externally controlled by a computer. Refer to Table 5-3 on page 5-5 and Table 5-4 on page 5-6 for a list of RS-232 commands and queries.

Turn-off (Complete Shut-down)

This procedure will remove all power from the Verdi and is recommended for performing system maintenance or if no operation is anticipated for extended periods of time. Use the cold-start procedure to turn the Verdi back on after a complete shut-down.

Complete shut-down can also be performed when the laser is externally controlled by a computer. Refer to Table 5-3 on page 5-5 and Table 5-4 on page 5-6 for a list of RS-232 commands and queries.

1. Turn the keyswitch power supply front panel to STANDBY.

2. Access and select the LBO Settings submenu. Press the MENU SELECT pushbutton to start the LBO cool-down cycle.

To avoid unnecessary use of the backup battery, do not turn the power switch on the power supply rear panel to the OFF position while the Verdi is in the cool-down cycle. This takes approximately 30 minutes.

3. During the cool-down cycle, the LBO temperature can be monitored from the main screen or the LBO Settings submenu. When the LBO temperature decreases below 40°C, turn the AC power switch on the power supply rear panel to the OFF position.

Removing AC power from the power supply will cause the internal battery to complete the LBO cool-down cycle. This causes unnecessary drain on the battery. For maximum battery life, use the LBO cool down menu. Refer to the paragraph titled, “Battery Backup” on page 7-8 for more information.

4. Turn off the chiller if equipped with the system.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Controls, Indicators, and Features

1. Emission indicator

2. Exit window

3. Clamps (4)

4. Riser/heat sink

5. Stable table clamps (4)

6. Umbilical

Figure 4-1. Laser Head Features

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Operation

Table 4-2. Laser Head Features

ITEM CONTROL FUNCTION

1 Emission indicator Lights when laser emission is possible.

2 Exit window 532 nm laser light is emitted from this window when the laser is on and the

shutter is open.

3 Clamps (4) Secures the laser head to the riser/heat sink.

4 Riser/Heat sink The passive riser/heat sink transfers heat from the laser head baseplate to

the mounting surface. The mounting surface must be capable of dissipating the transferred heat such that the baseplate temperature does not exceed 55°C.

The optional water-cooled riser/heat sink needs no additional mounting surface to maintain the base temperature below 55°C.

5 Optical table clamps (4) Secures the heat sink to the mounting surface.

The mounting surface must be capable of dissipating the transferred heat such that the baseplate temperature does not exceed 55°C.

6 Umbilical Houses the fiber optic and electrical cables that provides an interface

between the laser head and power supply.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

1. AC ON indicator

2. Key switch

3. LASER EMISSION indicator

4. Display

5. MENU UP/DOWN pushbuttons

6. MENU SELECT pushbutton

Figure 4-2. Power Supply Front Panel Controls and Indicators

9 10

7. MENU EXIT pushbutton

8. SHUTTER OPEN pushbutton indicator

9. DISPLAY CONTRAST adjust

10. POWER LEVEL 1/2 pushbutton indicators

11. POWER ADJUST knob

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Operation

Table 4-3. Power Supply Front Panel Controls and Indicators

ITEM CONTROL FUNCTION

1 AC ON indicator Lights when power is applied to the power supply via the power switch on

the rear panel.

2 Key switch The key switch can place the Verdi V-2/V-5/V-6 either in the STANDBY

or ON state. Functionality in these states are summarized in Table 4-1. The key can be removed when in STANDBY position to prevent unauthorized operation. The key cannot be removed when in ON position.

3 LASER EMISSION

indicator

4 Display Displays system status, operating parameters, and diagnostic data. Refer to

5 MENU UP/DOWN

pushbuttons

6 MENU SELECT push-

button

7 MENU EXIT push-

button

8 SHUTTER OPEN

pushbutton indicator

9 DISPLAY CONTRAST

adjust

10 POWER LEVEL 1/2

pushbutton indicators

Lights when laser emission is possible.

Figure 4-4 for a description of the displays.

Allows scrolling through the menus. Refer to Figure 4-4 for a description of the displays and menus.

Allows selection of the indicated menu.

Exits current menu. Can also be used to clear inactive faults as described in the troubleshooting charts in Section Six, Maintenance and Service.

Remotely opens and closes the external shutter on the laser head. When the shutter is closed, the laser will go to idle at minimum power. If the POWER ADJUST knob is not touched after the shutter is closed, the laser will return that power setting once the shutter is opened. If the POWER ADJUST knob is adjusted after the shutter is closed, then the laser will ramp to the new setting after the shutter is opened.

Allows adjustment of the display by user for best viewing.

Allows selection of 2 preset laser output power levels. To preset a power level, press the pushbutton to light the LED. Use the POWER ADJUST knob to set the power, then press the pushbutton again so that the LED is off. The new power value is then stored.

11 POWER ADJUST knob Allows continuous adjustment of output power level from threshold to

maximum power.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

1. Fuses

2. Power ON/OFF switch

3. Power cord

4. Umbilical

5. Air filter

6. Air filter retaining nuts (2)

7. Reserved connector

8. EXTERNAL INTERLOCK connector

9. SERIAL PORT connector

Figure 4-3. Power Supply Rear Panel Controls and Indicators

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Table 4-4. Power Supply Rear Panel Controls and Indicators

ITEM CONTROL FUNCTION

1 Fuse 250 V, 10 A, time delay fuse provides electrical protection.

2 Power ON/OFF switch Applies/removes all power from the Verdi V-2/V-5/V-6. Refer to the

shut-down procedures to avoid unnecessary use of the internal battery.

3 Power cord Connects the power supply to AC facility power.

4 Umbilical Houses electrical and fiber optic cables.

5 Air filter Removes dirt and contamination from the power supply cooling air.

6 Air filter retaining nuts Secures air filter to power supply.

7 Reserved connector Reserved for future use.

Operation

8 EXTERNAL INTER-

LOCK connector

9 SERIAL PORT

connector

Allows connection of an external interlock. The laser will not operate when this connector is open. Refer to the Section Three, Installation, for additional information on the interlock.

Allows external computer control of the Verdi V-2/V-5/V-6. Refer to Section Five for additional information on external computer control including commands, queries, and system requirements.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Menu Displays

Figure 4-4 shows the Verdi Main Display and the Base Menu screens. The Base Menu screen can be reached from the Main Display screen by pressing the SELECT pushbutton on the power supply front panel. Once in the Base Menu screen, the user can return to the Main Display screen by pressing the power supply EXIT pushbutton.

Navigation through a list of submenus, such as those in the Base Menu screen, is achieved by pressing the UP and DOWN arrow keys on the power supply front cover. When the selection arrow (see Figure 4-4) points to the desired submenu, that item can be activated by pressing the SELECT pushbutton. Pressing the EXIT pushbutton will deactivate the submenu, and re-display the Base Menu screen. Examples and explanations for all Verdi submenus can be found in Table 4-5.

to move arrow

Menu UP

Menu DOWN

Base Menu Servo Status Laser Status FAULT Status LBO Settings LBO Optimization Temperature Set Points RS-232 Baudrate Setup Etalon Capture Speaker Volume Diode Parameters

MAIN DISPLAY

Verdi V-6

Set Power:

6.00 W

System Status, Blank when System

is Locked at Set Power

STANDBY

Current:

20.43 A

SELECT

EXIT

System Status Messages

Figure 4-4. Menus

The current status of the laser system is displayed in the upper right-hand corner of the Main Display screen of the software (see Figure 4-4). Possible messages are:

• System Warming Up: Displayed while LBO crystal is.

heating.

• Standby. Displayed if power supply front panel keyswitch is

in the STANDBY position.

• Laser Seeking. Displayed while system is ramping the diode

current up to achieve set power. If the system is displaying this message while the diode current is not changing, one or more servo loops in the seek mode of operation. See the software Servo Status Screen for additional information.

• Shutter Closed. Displayed if system head shutter has not been

opened.

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Operation

• Fault Active. Displayed if there is an active system fault. See

the Fault Status Screen for additional information.

• RS-232 Key Standby. Displayed if the laser system is placed

in STANDBY via the RS-232 command.

Fault Handling

In case of a fault, the CPU closes the shutter, sets the laser diode current to zero, and displays the Fault Status Screen. For example:

!!!!!!!!!!!!!!!!!!!!!!!

FAULT CONDITION!

ERROR CODE #16

Diode 1 Over Current Fault

!!!!!!!!!!!!!!!!!!!!!!!

Push EXIT to continue

To clear a fault, the appropriate troubleshooting steps should be taken. The power supply keyswitch should be turned to the STANDBY position and the EXIT pushbutton pressed. See Table 6-1 on page 6-1 for a complete listing of system faults and troubleshooting procedures.

When the condition that caused the fault no longer exists, exit the Fault Status screen to clear the fault. Once the keyswitch is turned to the ON position, laser operation returns to its pre-fault state, except the shutter will remain closed.

If the fault condition still exists, the system message “FAULT ACTIVE” will be displayed in the Main Display screen.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Low Power Warning

If the system maximum diode drive current is reached, and the requested output power is not obtained, the power supply will beep and a “LOW POWER!!” warning message will be displayed in the lower right-hand corner of the Main Display screen.

Verdi V-6

Current:

Set Power 30.45 A

6.00 W

LOW POWER!!

(4.14 Watts)

Shutdown: 567 sec

If this message is observed, the output power setpoint should be decreased until it is less than the value in the warning message and the LBO optimization procedure should be run. If the warning message reappears after LBO optimization, contact your local Coherent service representative.

If the output power setpoint is not decreased, the system will shut down with a “Diode Over Current” fault after 600 seconds has elapsed.

Table 4-5. Submenus (Sheet 1 of 3)

Servo Status Screen

Servo: State W/deg C Drive

Laser: lock 5.00 21000

LBO: lock 146.00 4784

Vanadate: lock 30.00 -1776

Vanadate 2: lock 30.00 -1776

Etalon: lock 46.00 428

Diode 1: *seek 16.51 -1413

Laser Status Screen S/W Version : 8.82, 9/2/99 Heatsink #1 T : 22.32 C Baseplate T : 28.40 C HEAD Hrs : 54.75 Sys: 7/23/99 DIODE1 Hrs : 64.05 I: 24.40 A

Displays the Verdi servo status: “OPEN,” “LOCK,” “SEEK,” “*SEEK,” or “FAULT.” The value for the laser light loop servo is in Watts and the other values (temperature servos) are °C.

*SEEK indicates the algorithm optimizing the diode temperature is running. This algorithm optimizes the diode temperature such that maximum laser rod absorption of the IR pump is achieved. Functionally, this lowers the diode pump power, and thus operating current, necessary to achieve specified power. *SEEK is invoked automatically provided the system is running at 80% or greater output power.

Displays Verdi V-2/V-5/V-6 status and system information.

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Fault Status Screen

SYSTEM OK:

Operation

Table 4-5. Submenus (Sheet 2 of 3)

If faults are active, the fault codes and descriptions will be displayed. Refer to Table 6-1 on page 6-1 for a complete list of faults and associated corrective actions. Refer to the paragraph titled, “Fault Handling” for additional information on how to clear faults.

LBO Settings

T: 146.04 Set: 146.00

Drive: 4788

LBO Heating

Press SELECT to start COOLING Press EXIT for NO CHANGE

LBO Optimization

T: 143.90 Pwr: 4.74 Drv: 6007

OK to OPTIMIZE LBO Temp

Press SELECT to OPTIMIZE Tlbo Press EXIT to ABORT

Temperature Set Points Set Pt: 144.00 Drive: 5950.0 Read T: 144.00 Status: lock Set Pwr: 5.00W Avg I: 23.28A

->LBO Temperature Vanadate Temperature …Etalon Temperature Diode #1 Temperature

Displays the state of the LBO servo (heating or cooling).

Access this menu to initiate heating or cooling of the LBO crystal. For example, the cool-down cycle is initiated from this menu during the “Complete Shutdown” procedure.

This menu is used to initiate LBO optimization. See paragraph titled, “LBO Temperature Optimization” on page 6-40 for additional information and procedures regarding LBO optimization.

Displays the various system temperature set points, actual temperatures, and DAC drives required by the servo loops. Temperatures cannot be changed from this menu.

RS-232 Baudrate Setup

RS-232 Protocol: 38400, 8, N, 1

Use KNOB to adjust rate values

Press SELECT to ACCEPT

Press EXIT to ABORT

Allows adjustment of the baud rate (factory set to 19,200) for RS-232 communications. See paragraph titled, “Setting The Baud Rate” on page 5-3 for additional information on baud rate.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Table 4-5. Submenus (Sheet 3 of 3)

Etalon Capture Screen

Press SELECT to Capture Mode Press EXIT to return to menus

Speaker Volume Screen

-> Speaker Volume HIGH Speaker Volume MEDIUM Speaker Volume LOW Speaker Volume OFF

Press SELECT to change

Press EXIT when done

Diode Parameters Screen

Diode 1 Voltage : 1.80V Diode 1 Current : 17.50A Diode 1 Photocell : 2.50V

The Etalon Capture Screen momentarily reduces the diode current below lasing threshold to allow the single-frequency mode to re-center. Re-centering is implemented each time the laser is turned on.

The Speaker Volume Screen allows the audible beep (fault) volume to be adjusted.

Displays diode voltage, current, and photocell values for the diodes. Coherent recommends recording these values periodically to help assess the health of the system.

The diode photocell voltage should be approximately 2.50 V, at maximum output power level.

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External Computer Control

SECTION FIVE: EXTERNAL COMPUTER CONTROL

How to Interface Verdi Lasers

RS-232 Command Language

Instruction Syntax for RS-232 Communication

This section provides details on how to interface a Verdi V-2 /V- 5/ V-6 la ser to a r em ot e c om puter via the RS-232 connector on the rear of the power supply.

The RS-232 interface is based on a set of laser control instructions, consisting of commands that affect laser operation, and queries that request the laser to return status information to the host. The instruction set is sufficient to support user-written programs that emulate the functions of the Verdi front panel.

Communication with the Verdi is with two types of instructions:

• Commands which set the values of laser operating parameters.

• Queries which request the laser to return the value of an oper-

ating parameter.

Any instruction to the laser consists of a command or query written as a string of ASCII characters and terminated by a carriage return and linefeed (<CR><LF>) or a semicolon (;).

For example:

LASER = 1<CR><LF>

Switches the Verdi from STANDBY to ON.

?LIGHT<CR><LF>

Requests the laser to return the measured laser output power.

The laser will always respond to an instruction by returning a message terminated by a carriage return and linefeed. Table 5-1 lists the possible responses from the laser.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Table 5-1. Response from Laser after Receiving Instruction

INSTRUCTION

SENT TO LASER

ECHO OFF PROMPT OFF

ECHO OFF PROMPT ON

RESPONSE FROM LASER

ECHO ON PROMPT OFF

ECHO ON PROMPT ON

Command + <CR><LF>

Query + <CR><LF> Data + <CR><LF> Verdi> Data

Command + <CR><LF>

(Illegal operand)

Command <CR><LF>

(Illegal instruction)

Query<CR><LF>

(Illegal instruction)

1. Multiple items will be separated by the “&” character. For example, a list of system faults will be returned as “3&5&6.”

<CR><LF> Verdi><CR> <LF> Command

+ <CR><LF>

Query + Data

RANGE ERROR: + Command + <CR><LF>

Command Error: + Command + <CR><LF>

Query Error: + Query + <CR><LF>

+ <CR><LF>

Verdi> RANGE ERROR: + Command + <CR><LF>

Ver di > C om ma n d Error: + Command + <CR><LF>

Ver di > Q ue r y Error: + Query + <CR><LF>

+ <CR><LF>

Command + RANGE ERROR: + Command + <CR><LF>

Command + Command Error: + Command + <CR><LF>

Query + Query Error: + Query + <CR><LF>

Ver di > C om ma n d + <CR><LF>

Verdi> Query + Data + <CR><LF>

Ver di > C om ma n d + RANGE ERROR: + Command + <CR><LF>

Ver di > C om ma n d + Command Error: + Command + <CR><LF>

Ver di > Q ue r y + Query Error: +Query + <CR><LF>

For proper handshaking, communication programs should wait until the <CR><LF> has been returned from the laser before sending the next instruction.

ECHO Mode The Verdi provides an “echo” mode in which each character trans-

mitted to the laser is echoed to the host. This feature can be turned on or off using the ECHO command.

PROMPT Mode The Verdi provides a “prompt” mode for terminal operation in which

the laser returns; for example, “Verdi>” after each command. This feature can be turned on or off using the “PROMPT” command.

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External Computer Control

? The single character “?” may be substituted for “PRINT” in all

queries. For example:

?LIGHT is equivalent to PRINT LIGHT

= or : The single characters = and : are equivalent delimiters between

text and data in all commands. For example:

LASER = 0 is equivalent to LASER: 0

RS-232 Interface Connection

RS-232 Port Configuration

CONFIGURATION DCE, NO HANDSHAKING

Data bits 8

Stop bits 1

Parity none

The Verdi Laser’s RS-232 port configuration is described in Table 5-2, and typical cable requirements are shown in Figure 5-1. The 9-pin RS-232 port is configured as data communications equipment (DCE) device using only pins 2 (serial data out), 3 (serial data in) and 5 (signal ground). Handshake lines RTS, CTS, DTR and DSR (pins 4, 6, 7 and 8) are not used and have no connections inside the power supply.

Table 5-2. RS-232 Port Description

Baud rate User selectable:

Setting The Baud Rate

1200 2400 4800 9600 19200 (default factory setting) 38400 57600

The baud rate of the 9-pin RS-232 port can be adjusted through the “RS-232 Baudrate Setup” menu on the front panel (Figure 4-4 on page 4-12) or via the SERIAL BAUDRATE = NNN command described in Table 5-1 and Table 5-2. After the baud rate is changed,

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

COMPUTER

DB9

Transmit Data (TXD)

Receive Data (RXD)

Signal Ground (GND)

DB9

VERDI

Figure 5-1. RS-232 Pin Configuration

the new setting will be used until it is changed even if the system power is switched off.

To set the baud rate by the remote computer, send the SERIAL BAUDRATE = NNN command to the laser at the currently set baud rate. After sending this baud rate command, host computer communications port must be reinitialized to the new baud rate.

Instruction Set

The factory set baud rate is 19200.

When an RS-232 command is issued to change a setting, the display may not update to reflect the changes taking place in the system. The user should press MENU EXIT and MENU SELECT to update the display.

Tables 5-3 and 5-4 describe the instructions (long and short forms) for use in RS-232 with the Verdi.

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External Computer Control

Table 5-3. RS-232 Commands

COMMANDS ACTION PERFORMED

BAUDRATE = nnnnn

B=n

CHILLER Available only with Coherent-supplied chiller (part number1037271).

ECHO = n

E=n

EXIT SCREEN = 1

EXIT = 1

FLASH = 1

FL = 1

KNOB DOWN= 1

KNOBDN = 1

LASER = n

L=n

Sets the RS-232 Serial port baud rate to the specified value.

nnnnn = 1200, 2400, 4800, 9600, 19200, 38400, 57600.

= ON, = XX.X

If n = 0: turns echo OFF. Characters transmitted to the laser will not be echoed to the host.

If n = 1: turns echo ON. Characters transmitted to the laser will be echoed to the host.

A change in echo mode will take effect with the first command sent after the echo command.

Duplicates EXIT button.

Flashes laser output below lasing threshold to allow single-frequency mode (Etalon) to recenter.

Duplicates KNOB DOWN button.

If n = 0: puts laser in STANDBY (note: If the key is in the “ON” position, then n = 0 will override)

If n = 1: resets faults and turns laser on (key must be in the “ON” position) Clears fault screen on power supply and fault history (?FAULT HISTORY) so lasing will resume if no active faults

LBO HEATER = n

LBOH = n

LBO OPTIMIZE = n

LBOOPT

LIGHT = nn.nnnn

P = nn.nnnn

LOCK FRONT PANEL = n

LFP = n

MENU DOWN = 1

MENUDN = 1

MENU SELECT= 1

SELECT = 1

MENU UP = 1

MENUUP= 1

If n = 0: turns LBO heater off (COOL DOWN)

If n = 1: turns LBO heater on (HEATING)

Initiates the LBO optimization.

1 = optimize

Sets light regulation to the specified output power.

Disables user input from the front panel.

Duplicates MENU DOWN button.

Duplicates MENU SELECT button.

Duplicates MENU UP button.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Table 5-3. RS-232 Commands (Continued)

COMMANDS ACTION PERFORMED

POWER = n

P = nn.nnnn

PRINT Works the same as a query; must be followed by a space

PROMPT = n

>=n

SHUTTER = n

S=n

Sets light regulation to the specified output power.

If n = 0: turns “Verdi>” prompt on

If n = 1: turns “Verdi>” prompt off

If n = 0: closes external shutter

If n = 1: opens external shutter

Table 5-4. RS-232 Queries (Sheet 1 of 5)

QUERIES RETURNED INFORMATION

PRINT AVG CURRENT AND DELTA

?ACAD

PRINT BASEPLATE TEMP

?BT

PRINT BAUD RATE

Returns the average diode current and the difference between them.

Returns laser head baseplate measured temperature, nn.nn, in °C.

Returns the baud rate of the Verdi V-2/V-5/V-6 serial port.

PRINT CURRENT

PRINT DIODE1 CURRENT

?D1C

PRINT DIODE1 HEATSINK TEMP

?D1HST

PRINT DIODE1 HOURS

?D1H

PRINT DIODE1 PHOTOCELL

?D1PC

PRINT DIODE1 RATED CURRENT FACTOR

?D1RCF

PRINT DIODE1 RATED CURRENT MAX

?D1RCM

Returns the measured average diode current, nn.n, in amps.

Returns laser diode #1 measured current, nn.n, in amps.

Returns laser diode #1 heat sink measured temperature, nn.nn, in °C.

Returns the number of operating hours on laser diode 1.

Returns light output power from diode 1 photocell.

Returns the factor that accounts for diode aging for diode 1.

Returns the maximum current at which diode 1 will be allowed to operate.

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External Computer Control

Table 5-4. RS-232 Queries (Sheet 2 of 5)

QUERIES RETURNED INFORMATION

PRINT DIODE1 SERVO STATUS

?D1SS

PRINT DIODE1 SET TEMP

?D1ST

PRINT DIODE1 TEMP DRIVE

?D1TD

PRINT DIODE1 TEMP

?D1T

PRINT DIODE1 5VREF SENSE

?D15V

Returns the status of diode #1 temperature servo:

0 if the servo is OPEN

1 if the servo is LOCKED

2 if the servo is SEEKING

3 if the servo has a FAULT

4 if the servo is OPTIMIZING

5 if the servo is CPEAKING (Not available for V5 UNO, V6)

6 if the servo is CPEAKING2 (For V5 UNO, V6 only)

Returns laser diode #1 set temperature, nn.nn, in °C.

Returns laser diode #1 temperature servo drive setting.

Returns laser diode #1 measured temperature, nn.nn, in °C.

Returns a reference voltage used to measure the temperature of Diode 1.

PRINT DIODE OPTIMIZER STATUS

?DIOS

PRINT ETALON DRIVE

?ED

PRINT ETALON SERVO STATUS

?ESS

PRINT ETALON SET TEMP

?EST

PRINT ETALON TEMP

?ET

Returns diode optimizer status.

1 if the system is able to optimize

0 if not

Returns etalon temperature servo drive setting.

Returns the status of the etalon temperature servo:

0 if the servo is OPEN.

1 if the servo is LOCKED.

2 if the servo is SEEKING.

3 if the servo has a FAULT.

Returns etalon set temperature, nn.nn, in °C.

Returns measured Etalon temperature, nn.nn, in °C.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Table 5-4. RS-232 Queries (Sheet 3 of 5)

QUERIES RETURNED INFORMATION

PRINT FAULTS

PRINT FAULT HISTORY

?FH

PRINT HEAD_HOURS

?HH

PRINT KEYSWITCH

1 = Laser Head Interlock Fault

2 = External Interlock Fault

3 = PS Cover Interlock Fault

4 = LBO Temperature Fault

5 = LBO Not Locked at Set Temp

6 = Vanadate Temp. Fault

7 = Etalon Temp. Fault

8 = Diode 1 Temp. Fault

10 = Baseplate Temp. Fault

11 = Heatsink 1 Temp. Fault

16 = Diode 1 Over Current Fault

Returns a list of number codes (see ?F) for all faults that have occurred since the last LASER ON command, separated by an “&”, or return SYSTEM OK if no latched faults. To clear the fault screen, when the fault is active, enter the LASER ON command or the EXIT button on the power supply

Returns the number of operating hours on the system head.

Returns:

0 if the keyswitch is OFF

1 if the keyswitch is ON

18 = Over Current Fault

19 = Diode 1 Under Volt Fault21 = Diode 1 Over Volt Fault25 = Diode 1 EEPROM Fault27 = Laser Head EEPROM Fault

28 = Power Supply EEPROM Fault

29 = PS-Head Mismatch Fault

31 = Shutter State Mismatch

40 = Head-Diode Mismatch Fault

47 = Vanadate2 Temp. Fault

PRINT LASER

PRINT LBO DRIVE

?LBOD

PRINT LBO HEATER

?LBOH

PRINT LBO OPTIMIZER STATUS

?LBOOS

PRINT LBO SET TEMP

?LBOST

Returns:

0 if the laser is OFF (STANDBY)

1 if the laser is in ON

2 if the laser is OFF due to fault (check faults or fault history)

Returns LBO temperature servo drive setting.

Returns the status of the LBO heater:

0 if the LBO heater is OFF (COOL DOWN)

1 if the LBO heater is ON (HEATING)

Returns the LBO optimizer status:

1 if the system is able to run the LBO optimization

0 if not

Returns LBO set temperature, nnn.nn, in °C.

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External Computer Control

Table 5-4. RS-232 Queries (Sheet 4 of 5)

QUERIES RETURNED INFORMATION

PRINT LBO SERVO STATUS

?LBOSS

PRINT LBO TEMP

?LBOT

PRINT LIGHT

PRINT LIGHT REG STATUS

?LRS

PRINT MODE

Returns the status of the LBO temperature servo:

0 if the servo is OPEN

1 if the servo is LOCKED

2 if the servo is SEEKING

3 if the servo has a FAULT

4 if the servo is OPTIMIZING

5 if the servo is CPEAKING (Not available for V5 UNO, V6)

6 if the servo is CPEAKING2 (Only available for V5 UNO, V6)

Returns LBO measured temperature, nnn.nn, in °C.

Returns the calibrated output power, nn.nnn, in watts.

Returns the status of the light loop servo:

0 if the servo is OPEN (current regulation)

1 if the servo is LOCKED

2 if the servo is SEEKING

3 if the servo has a FAULT

Returns the mode of operation, whether current or light control.

1= light, 0= current

PRINT PS HOURS

?PSH

PRINT SET LIGHT

?SP

PRINT SHUTTER

PRINT SOFTWARE

?SV

PRINT VANADATE SET TEMP

?VST

PRINT VANADATE TEMP

?VT

Returns the number of power supply operating hours.

Returns the light regulation set power, nn.nnnn, in watts.

Returns the status of the external shutter:

0 if the shutter CLOSED

1 if the shutter OPEN

Returns the power supply software version number.

Returns vanadate #1 set temperature, nn.nn, in °C

Returns vanadate #1 measured temperature, nn.nn, in °C.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Table 5-4. RS-232 Queries (Sheet 5 of 5)

QUERIES RETURNED INFORMATION

PRINT VANADATE DRIVE

?VD

PRINT VANADATE SERVO STATUS

?VSS

Returns vanadate #1 temperature servo drive setting

Returns the status of the vanadate temperature servo:

0 if the servo is OPEN

1 if the servo is LOCKED

2 if the servo is SEEKING

3 if the servo has a FAULT

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Maintenance and Service

SECTION SIX: MAINTENANCE AND SERVICE

Do not open the Verdi V-2/V-5/V-6 laser head. There are no user-serviceable components or adjustments inside. There are hazardous levels of laser energy inside the laser head. There is no cover interlock to eliminate these dangers upon removal of the laser head cover.

Troubleshooting

Table 6-1 lists possible problems/error messages with a reference to the associated troubleshooting chart located in this section.

Table 6-1. Troubleshooting/Fault Messages (Sheet 1 of 3)

PROBLEM

Laser does not start (no laser output) Chart 1

Laser shuts down Chart 2

Laser output unstable Chart 3

AC ON indicator on power supply front panel does not light when power switch on rear panel is on.

LASER EMISSION indicator on power supply front panel or on the laser head does not light when keyswitch is in the “ON” position.

TROUBLESHOOTING

REFERENCE

Chart 4

See note [1]

Diode currents increase by 10% of baseline current. Chart 11

[1] Contact Coherent or an authorized representative. If the laser system or components are being returned directly

to Coherent, an RMA (Return Material Authorization) number is required.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Table 6-1. Troubleshooting/Fault Messages (Sheet 2 of 3)

PROBLEM

TROUBLESHOOTING

REFERENCE

FAULT MESSAGES:

Fault Code 1: Laser Emission Lamp Fault Chart 5

Fault Code 2: External Interlock Fault Chart 6

Fault Code 3: PS Cover Interlock Fault Chart 7

Fault Code 4: LBO Temperature Fault Chart 8

Fault Code 5: LBO Not Locked at Set Temperature Chart 12

Fault Code 6: Vanadate Temperature Fault Chart 8

Fault Code 7: Etalon Temperature Fault Chart 8

Fault Code 8: Diode 1 Temperature Fault Chart 8

Fault Code 10: Baseplate Temperature Fault Chart 9

Fault Code 11: Diode Heat Sink 1 Temperature Fault Chart 10

Fault Code 16: Diode 1 Over Current Fault Chart 11

Fault Code 18: Over Current Fault Chart 11

Fault Code 19: Diode 1 Under Voltage Fault Chart 12

Fault Code 21: Diode 1 Over Voltage Fault Chart 12

Fault Code 25: Diode 1 EEPROM Fault Chart 12

Fault Code 27: Laser Head EEPROM Fault Chart 12

Fault Code 28: Power Supply EEPROM Fault Chart 12

Fault Code 29: Power Supply-Head Mismatch Fault Chart 12

Fault Code 30: Battery Requires Service Chart 13

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Maintenance and Service

Table 6-1. Troubleshooting/Fault Messages (Sheet 3 of 3)

PROBLEM

Fault Code 31: Shutter State Mismatch Chart 12

Fault Code 40: Head-Diode Mismatch Fault Chart 12

TROUBLESHOOTING

REFERENCE

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 1. Laser Does Not Start (No Light Output)

Start

Refer to the assumptions on the facing page

[1]

AC power indicator lit?

YES

Display visible?

YES

Any fault messages displayed? Clear fault? Fault active?

YES

Refer to Chart 4.

Contact Coherent service or an authorized service representative.

Shutter Open?

YES

[2]

Refer to Table 6-1.

Contact Coherent service or an authorized service representative.

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Maintenance and Service

Chart 1. Laser Does Not Start (No Light Output) [Continued]

The numbered paragraphs below are keyed to supplement this flowchart.

[1] ASSUMPTIONS:

• The laser system has been installed in accordance with the installation procedures in Section Three:

Installation.

• This procedure is not intended to re-start a laser after it has shut down due to a fault.

• A closed shutter is not blocking output light.

• The appropriate turn-on procedures are performed and the laser is not in a warm-up cycle.

[2] If the laser system must be returned directly to Coherent, an RMA (Return Material Authorization) number

is required. Contact Coherent or an authorized representative.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 2. Laser Shuts Down (No Light Output)

Start

Refer to the assumptions on the facing page

[1]

AC indicator on?

YES

Any fault messages displayed?

YES

Refer to Table 6-1.

Refer to Chart 4.

Contact Coherent service or an authorized service representative.

[2]

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Maintenance and Service

Chart 2. Laser Shuts Down (No Light Output) [Continued]

The numbered paragraphs below are keyed to supplement this flowchart.

[1] ASSUMPTIONS:

• The laser system had been operating immediately prior to shutdown.

• The interlocks are closed as described in Section Three: Installation. The laser will not operate with

an interlock circuit open.

If a user interlock is installed, the user interlock can be verified by temporarily replacing it with the interlock supplied with the system.

[2] If the laser system must be returned directly to Coherent, an RMA (Return Material Authorization) number

is required. Contact Coherent or an authorized representative.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 3. Laser Output Unstable

Start

Refer to the assumptions on the facing page

[1]

Any fault messages displayed?

Use the Etalon Capture screen to flash laser. Power unstable?

YES

Check output power with an external power meter. Power unstable?

YES

Contact Coherent service or an authorized service representative.

[2]

[3]

YES

Refer to Table 6-1.

End

Contact Coherent service or an authorized service representative.

[3]

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Maintenance and Service

Chart 3. Laser Output Unstable [Continued]

The numbered paragraphs below are keyed to supplement this flowchart.

[1] ASSUMPTIONS:

• The laser system has been installed in accordance with the installation procedures in Section Three:

Installation.

[2] Refer to Figure 4-4 on page 4-12 to access the Etalon Capture Screen. Press SELECT from within the

screen to flash the laser.

[3] If the laser system must be returned directly to Coherent, an RMA (Return Material Authorization) number

is required. Contact Coherent or an authorized representative.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 4. AC ON Indicator Does Not Light

Start

Refer to the assumptions on the facing page

[1]

Other indicators on power supply front panel lit?

YES

Contact Coherent service or an authorized service representative.

[4]

Verify facility power. Facility power OK?

Correct facility power as required.

YES

Check power supply fuse. Fuse OK?

Replace fuse.

YES

[2]

[3]

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Maintenance and Service

Chart 4. AC ON Indicator Does Not Light [Continued]

The numbered paragraphs below are keyed to supplement this flowchart.

[1] ASSUMPTIONS:

• The laser system has been installed in accordance with the installation procedures in Section Three:

Installation.

• The power cord is connected to an active facility power source and the power switch on the power

supply rear panel is on.

[2] After performing the “Turn-off (Complete Shut-down)” on page 4-5”, disconnect the laser system from

facility power and remove the fuse (Figure 4-3 on page 4-10, item 1) using the fuse replacement procedures located in this section. Verify continuity (closed circuit) between the two fuse terminals.

[3] Refer to the fuse replacement procedures located in this section. If the fault persists, contact Coherent or

an authorized representative.

[4] If the laser system must be returned directly to Coherent, an RMA (Return Material Authorization) number

is required. Contact Coherent or an authorized representative.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 5. Head Laser Emission Lamp Fault

[1] Press MENU EXIT to clear the fault display.

If the fault does not clear, a fault message will appear on the Main Display and on the Fault Status menu (Figure 4-4 on page 4-12).

If the fault clears, open the shutter and resume operation.

[2] Ensure the umbilical is not strained or cut and that bend radius of the optical fiber is five inches or greater.

[3] Turn the power switch on the power supply rear panel to the OFF position for approximately 20 seconds.

Then turn the switch back to the “on” position.

[4] If the fault persists, contact Coherent or an authorized representative. If the laser system must be returned

directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

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Maintenance and Service

Chart 6. External Interlock Fault

The laser system will not operate with an open interlock circuit. Ensure the external interlock is supplied with the system or a user furnished interlock is installed. See paragraph titled, “External Interlock” on page 3-7 for more information on the external interlock.

[1] Press MENU EXIT to clear the fault display.

If the fault does not clear, a fault message will appear on the Main Display and on the Fault Status menu (Figure 4-4 on page 4-12).

If the fault clears, open the shutter and resume operation.

[2] Ensure the EXTERNAL interlock connector on the power supply rear panel is firmly seated.

[3] If a user interlock is installed, turn the keyswitch to STANDBY and replace the user interlock circuit with

the external interlock supplied with the system. If the fault clears, the user interlock circuit is defective.

If the fault does not clear, verify continuity of the interlock connector.

If the fault clears, open the shutter and resume operation.

[4] Turn the power switch on the power supply rear panel to OFF position for approximately 20 seconds. Then

turn the switch back to the “on.”

[5] If the fault persists, contact Coherent or an authorized representative. If the laser system must be returned

directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 7. PS Interlock Fault

To ensure the top cover of the power supply is secure, turn the keyswitch to the STANDBY position and verify the power supply top cover is closed with all fasteners fully tightened.

[1] Press MENU EXIT to clear the fault display.

If the fault does not clear, a fault message indication will appear on the Main Display and on the Fault Status menu (Figure 4-4 on page 4-12).

If the fault clears, open the shutter and resume operation.

[2] Turn the power switch on the power supply rear panel to OFF position for approximately 20 seconds. Then

turn the switch back to the “on.”

[3] If the fault persists, contact Coherent or an authorized representative. If the laser system must be returned

directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

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Maintenance and Service

Chart 8. LBO Temperature Fault

Vanadate Temperature Fault Etalon Temperature Fault Diode 1 Temperature Fault

[1] Press MENU EXIT to clear the fault display.

If the fault does not clear, a fault message will appear on the Main Display and on the Fault Status menu (Figure 4-4 on page 4-12).

If the fault clears, open the shutter and resume operation.

[2] Verify the set points in the “Temperature Set Points” submenu are the same as on the test sheet. If a diode

or LBO optimization has been performed, verify their temps are the same from the last optimization. If different, contact Coherent or an authorized representative.

[3] Turn the power switch on the power supply rear panel to OFF position for approximately 20 seconds. Then

turn the switch back to the “on.”

[4] If the fault persists, contact Coherent or an authorized representative. If the laser system must be returned

directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 9. Baseplate Temperature Fault

[1] Press MENU EXIT to clear the fault display.

If the fault does not clear, a fault message will appear on the Main Display and on the Fault Status menu (Figure 4-4 on page 4-12).

If the fault clears, open the shutter and resume operation.

[2] Verify the laser head is installed on a riser/heat sink and the riser/heat sink is located on a surface that will

dissipate heat at a rate that will maintain the baseplate temperature below 55°C.

Ensure that the ambient temperature is not excessively high and the laser head is not located near a heat generating source.

If a suitable ambient temperature cannot be maintained or if the laser head must be located in a less than optimum location, an optional water cooled riser/heat sink is available from Coherent.

[3] Turn the power switch on the power supply rear panel to OFF position for approximately 20 seconds. Then

turn the switch back to the “on.”

[4] If the fault persists (and the ambient temperature and laser head location meet the above requirements),

contact Coherent or an authorized representative. If the laser system must be returned directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

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Maintenance and Service

Chart 10. Diode Heat Sink Temperature Fault

[1] Press MENU EXIT to clear the fault display.

Turn the keyswitch on the power supply front panel to STANDBY.

[2] Verify the following conditions are true:

• The cooling fans are not obstructed

• The rear, top, and left side of the power supply are not obstructed

• The air filter is not clogged (do not remove the air filter when the fans are rotating)

• The power supply is not located near a heat source

• The ambient temperature is not excessively high

[3] Turn the power switch on the power supply rear panel to OFF position for approximately 20 seconds. Then

turn the switch back to the “on.”

[4] If the fault persists (and the ambient temperature and power supply location meet the above requirements),

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Verdi V-2/V-5/V-6 Laser Operator’s Manual

Chart 11. Diode Over Current Fault

Over Current Fault 10% Current Increase (No Fault)

Start

Refer to the assumptions on the facing page

[1]

Set the output power to highest sustainable power Fault active?

Optimize the LBO temperature. Spec power is achieved with no fault displayed?

Contact Coherent service or an authorized service representative.

[4]

[2]

[4]

YES

[3]

YES

Contact Coherent service or an authorized service representative.

End.

[4]

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Chart 11. Diode Over Current Fault [Continued]

Over Current Fault 10% Current Increase (No Fault)

[1] ASSUMPTIONS:

• The laser system has been installed in accordance with the installation procedures in Section Three:

Installation.

[2] If the fault is displayed, press EXIT to clear the fault.

[3] Use the LBO Optimization menu shown in Figure 4-4 on page 4-12 to perform the optimization routine.

[4] If the laser system must be returned directly to Coherent, an RMA (Return Material Authorization) number

is required. Contact Coherent or an authorized representative.

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Chart 12. Diode Under Voltage Fault

Diode Over Voltage Fault Diode EEPROM Fault LBO Not Locked at Set Temperature Laser Head EEPROM Fault Power Supply EEPROM Fault Power Supply-Head Mismatch Fault Shutter State Mismatch Head-Diode Mismatch Fault

[1] To clear a fault, the power supply keyswitch should be turned to the STANDBY position, and the EXIT

push button pressed. If the fault condition no longer exists, exiting the Fault Status screen will clear the fault. Once the keyswitch is turned to the ON position, laser operation returns to the state it was in before the fault occurred except the shutter will be closed. If the fault condition still exists, the system message “FAULT ACTIVE” will be displayed in the Main Display screen.

If the fault does not clear, a fault message will continue to appear on the Fault Status menu (Figure 4-4 on page 4-12).

If the fault clears, open the shutter and resume operation.

Note: it may be necessary to wait for the LBO crystal to lock at the set temperature before resuming operation.

[2] Turn the power switch on the power supply rear panel to OFF position for approximately 20 seconds. Then

turn the switch back to the “on.”

[3] If the fault persists, contact Coherent or an authorized representative. If the laser system must be returned

directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

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Chart 13. Battery Requires Service

[1] To clear a fault, press the MENU EXIT pushbutton and perform the complete shutdown. Wait at least five

seconds before turning the system on. Upon turn-on, verify the status of the system.

If the fault clears, open the shutter and resume operation.

Note: it may be necessary to wait for the LBO crystal to lock at the set temperature before resuming operation.

[2] If the fault persists, perform the procedure in paragraph titled, “Battery Replacement” on page 6-42. If the

fault still persists after replacing the battery, the laser system must be returned to Coherent. A Return Material Authorization (RMA) number is required. Contact Coherent or an authorized representative for more information or to receive an RMA number.

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FAP-I Replacement

Preliminary Steps and Data

Refer to Table 6-1 for the troubleshooting charts prior to replacing the FAP-I. Contact Coherent technical support or a local service representative to assist in determining the need for FAP-I replacement.

1. With the laser system in STANDBY, record the following system parameters from the “Temperature Set Points” submenu:

a. LBO temperature set point

b. Vanadate temperature set points

c. Etalon temperature set point

d. FAP-I temperature set point

2. Perform the “Turn-off (Complete Shut-down)” on page 4-5. The associated cool-down cycle takes approximately 30 minutes. The front panel display indicates when the cool-down cycle is complete.

Do not turn the power switch on the rear panel to the OFF position or disconnect the AC power input until the cool-down cycle is complete.

3. When the LBO cool-down cycle is complete, turn the power switch on the power supply rear panel to the OFF position.

Do not disconnect the power cord from facility power. The power supply chassis must be grounded either by the power cord or a separate ground to avoid electro-static discharge (ESD).

4. Remove the top cover of the power supply.

The FAP-I can be damaged by electro-static discharge (ESD). To avoid ESD, a personal grounding strap must be used at all times.

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Maintenance and Service

FAP-I Handling Precautions

1. The FAP-I can be damaged by improper ESD handling. To avoid ESD, a personal grounding strap must be used at all times. Follow the instructions that accompany the personal grounding strap.

6 inch Fiber Looping

FAP-I # 1

Figure 6-1. Location of FAP-I Assemblies and Fiber Looping

2. A shorting clip (Figure 6-2) must be installed between the anode and cathode terminals to avoid inadvertent ESD before the leads are disconnected from the terminals.

3. When disconnecting the fiber optic cable from the FAP-I assembly, a cap (Figure 6-2) must be installed over both the FAP-I optical emission port and the end of the fiber optic cable to protect them from accidental damage or contamination.

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Figure 6-2. Fiber Optic Covers and FAP-I Anode/Cathode Shorting Clip

Fiber Cable Handling Precautions

The end of the fiber optic cable is an optical surface. Do not allow the end of the fiber optic cable to make contact with any surface, including the fingers.

A contaminated optical surface can cause system damage. To minimize exposure to contaminants, the blue protective plastic cap must be installed whenever the fiber is disconnected.

When removing or installing the fiber optic cable, do not allow the fiber optic cable to rotate while loosening the ferrule connector.

1. When removing or installing a fiber optic cable, do not allow the fiber optic cable to rotate while loosening the ferrule connector (Figure 6-4).

2. The end of the fiber optic cable is an optical surface. Do not allow the end of the fiber optic cable to contact any surface, including the fingers. To minimize exposure to the environment, the protective plastic cap must be left in place until a

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Maintenance and Service

connection is made and immediately installed over the fiber end when a connection is disassembled.

3. Do not allow the end of the fiber optic cable to contact the diode (FAP-I) assembly or any other surface including the fingers. Failure to do so can damage the optical surface.

Inspect the fiber optical surface to verify the cleaning procedure is necessary.

4. Do not install a contaminated or damaged fiber optic cable to the FAP-I. Doing so will cause a failure of the laser system. Contamination or damage can be difficult to detect. A magnifying glass may help during the inspection

Do not use acetone as a cleaning solvent on fiber optical surfaces. It will dissolve the matrix that supports the fiber and will destroy the optical transport fiber permanently.

FAP-I Removal

5. The end of the fiber optic cable should be cleaned using the “Drop and Drag” procedure. Refer to the paragraph titled, “LBO Temperature Optimization” on page 6-40. Do not use any other procedure or method. If scratches or other damage is present, the FAP-I replacement should be terminated and the plastic cap reinstalled. Contact Coherent or an authorized local representative.

6. Excessively tight fiber umbilical bends (less than a 3-inch radius) can cause permanent damage to the transport fiber.

1. Install shorting clip (Figure 6-2) between anode and cathode of FAP-I assembly to be removed. Disconnect the anode and cathode connectors, see Figure 6-3.

2. Disconnect the Case/Anode ground jumper from the FAP-I assembly.

Wear finger cots (supplied with the replacement FAP-I) while handling the fiber optic cable.

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1. Anode Connector Terminal

2. Cathode Connector Terminal

3. Case/Anode Ground Jumper

4. Fiber Optic Connector and Optical Emission Port

5. Personality Module, Thermistors, Diode Hours Connector

6. TEC Coolers Inputs/Outputs Connector

7. Fiber Optic Cable

Figure 6-3. FAP-I Assembly Interface

3. Disconnect the fiber optic cable as follows:

a. While firmly holding the fiber optic cable, loosen the

ferrule connector securing the fiber optic cable to the FAP-I. It may be necessary to use a small wrench to loosen the connector.

b. Note the ferrule cutout (see Figure 6-4). Carefully

extract the fiber optic cable from the FAP-I and remove the ferrule.

c. Immediately install the two plastic protective caps, one

over the end of the fiber cable and the second over the FAP-I optical output port (Figure 6-2).

4. Disconnect the Personality module and TEC connectors from the FAP-I assemblies by pulling back on the outer sleeve and then unplugging the connector.

5. Remove the eight screws securing the FAP-I to the heat sink (two on each side).

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Ferrule Cutout

Maintenance and Service

Due to the thermal grease on the bottom of the FAP-I assembly, it may be necessary to work the old assembly loose by rotating (wiggling) it back and forth around its center.

6. Remove the FAP-I from the power supply and clean the thermal grease from the FAP-I and the mounting surface (alcohol works well for this).

Proper Installation, Anode Lead (red) Horizontally Oriented

FAP-I Installation

Proper Installation, Cathode Lead (black) Vertically Oriented

Figure 6-4. FAP-I Fiber Optic Connector

The following items are included in the FAP-I installation kit:

• FAP-I ass embl y

• Die-cut plastic masking sticker

• Tube of thermal compound

• Plastic spatula for spreading thermal compound

• Fiber optic cap

• Finger cot for fiber handling

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1. Remove the new FAP-I from the shipping container. Leave the shorting clip and protective plastic cap in place to avoid possible ESD and contamination damage.

2. Apply the die-cut template to the bottom of the diode to avoid contaminating the screw holes with thermal compound in the next step. Alternatively, place masking tape over the edges of the FAP-I baseplate as illustrated in Figure 6-5.

3. Using the plastic applicator, apply an even coating of thermal grease to the bottom of the FAP-I. The thickness of the grease film should be less than the thickness of the masking tape or template.

4. Remove the template or masking tape.

5. Position the FAP-I assembly on the heat sink.

6. Re-attach the Case/Anode ground jumper to the FAP-I baseplate.

7. Secure the FAP-I to the heat sink using the remaining seven mounting screws.

8. Remove any excess thermal grease from around the assembly.

Figure 6-5. Preparation of the Replacement FAP-I Assembly

After connection, the red anode lead should be horizontally oriented and the black cathode lead should be vertically oriented. This is illustrated in Figure 6-4 and minimizes the potential of generating/picking up EM noise.

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Maintenance and Service

9. Re-connect the anode and cathode leads. Be sure to reconnect the case/anode ground jumper when connecting the anode lead.

10. Remove the anode/cathode shorting clip.

11. Re-connect the Personality module and TEC connectors.

12. Inspect, and, if necessary, clean the fiber optic surface. (See the procedure titled “LBO Temperature Optimization” below).

13. Re-connect the fiber optic cable to the FAP-I, securing the nut finger-tight (no more than 4 in-lbs. if using a torque wrench).

14. If disconnected, re-connect the AC power cord to facility power. If a ground wire was used, remove it.

15. Replace the power supply cover and perform the procedure in paragraph titled, “Turn-on (Cold-Start)” on page 4-2.

16. Verify system parameters.

Fiber Optic Cleaning

Before performing the cleaning procedure, inspect the fiber optic surface with a fiberscope or magnifier to determine the extent to which the fiber might be damaged or contaminated. Only perform the cleaning procedure if the fiber optic surface shows imperfections, otherwise the procedure may introduce dust, dirt, or potentially induce damage to the fiber optic. Reference the figures titled “Good Fiber” on page 6-38, “Bad or Questionable Fibers” on page 6-38, and “Guidelines for Fiber Optic Inspection” on page 6-39 to determine if the fiber requires cleaning and/or replacement.

The Drop and Drag method is the least abrasive cleaning method and should always be used first to remove imperfections on the fiber optic surface. If the Drop and Drag method will not remove particulates, then the fiber optic surface should be cleaned with a cleanroom swab. The cleanroom swab is most effective; however, a lens tissue with a hemostat may be used as an alternative to the cleanroom swab.

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Equipment Needed

The following materials are required to perform this procedure:

• Lens cleaning tissue

• Cleanroom-quality swabs

(Coherent recommends using Micro Alpha Swab ESD, Part #1488-758E from Cintas at (800) 786-6027)

Lens tissue and a hemostat may be used as an alternative to the swabs.

• Fresh spectroscopic-grade Methanol

• Fiber microscope (fiberscope), 200X total magnification

• Non-powdered, non-coated Latex (or equivalent) gloves or

fingercots

Important: Do not use Acetone! Acetone will dissolve adhesives used in the manufacture of the fiber optic and will destroy the fiber optic cable.

Fiberscope

Procedure

Drop and Drag Procedure

A recommended cost-effective fiberscope is the OFS 300-200C model with 20X eyepiece and SMA adapter manufactured by Noyes™. See Figure 6-6.

Always wear latex gloves or fingercots (or the equivalent) while performing any of the following procedures. Fingerprints, dust, condensation, and oils from the hand can damage the fiber optic surface.

1. Using a medicine dropper and a new, clean lens tissue, put one drop of Methanol near the center of the lens tissue. See Figure 6-7.

2. Holding the fiber vertically so the fiber surface points to the ceiling, carefully place the tissue so the optical surface rubs against the underside of the tissue. See Figure 6-8.

3. In a single movement, gently drag the fiber surface against the underside of the wet tissue in a circle, spiraling out, taking care not to go over the same part of the tissue twice. See Figure 6-9.

Drag the fiber out from the saturated part of the tissue to the

dry parts of the tissue, which dries the fiber optic surface and prevents Methanol residue.

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Maintenance and Service

Figure 6-6. Fiberscope with 20X Eyepiece and SMA Adapter

4. Re-check the fiber with the fiberscope.

If the fiber surface is now ideal or complies with the acceptable guidelines as illustrated in Figure 6-19 on page 6-39, immediately install the fiber optic into the FAP-I/FAP-B.

If the imperfections have not been removed, or if any Methanol residue has been induced (See Figure 6-10), continue with the cleanroom swab procedure below.

Figure 6-7. Methanol Drop on Lens Tissue

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Figure 6-8. Placement of the Fiber Optic Against the Lens Tissue

Figure 6-9. Movement of Fiber Optic Against Lens Tissue

Methanol residue can cause burn spots or potentially catastrophic damage to the fiber optic and the FAP-I/FAP-B. See Figure 6-10 for an illustration of Methanol residue.

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Figure 6-10. Methanol Residue

Maintenance and Service

Cleanroom Swab Procedure

Using lens tissue and a hemostat may be substituted for the cleanroom swab procedure. Reference the procedure titled “Alternative Cleaning Procedure” on page 6-35 for the alternate method.

1. Using a medicine dropper, put one to two drops of Methanol on the swab (Figure 6-11).

2. Vigorously shake off excess Methanol from the swab to prevent Methanol residue.

Only the synthetic cloth should make contact with the fiber optic surface. Do not allow the plastic applicator to touch the fiber surface.

3. Holding the fiber vertically so the fiber surface points to the ceiling, carefully place the base of the swab against the fiber optic surface, taking care not to touch the plastic applicator to the fiber optic surface. See Figure 6-12.

4. Drag the swab across the fiber optic surface in a single stroke. Do not drag the swab back and forth.

5. Repeat Step 4 using the other side of the swab.

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Figure 6-11. Methanol Drop

Figure 6-12. Placement and Movement of the Swab Against the Fiber Optic Surface

6. Re-check the fiber using the fiberscope.

If the fiber surface is now ideal or complies with the acceptable guidelines as illustrated in Figure 6-19 on page 6-39, immediately install the fiber optic into the FAP-I/FAP-B.

If imperfections remain, repeat the procedure using a new swab.

7. If imperfections still remain, compare the image in the fiberscope with Figure 6-19 on page 6-39 and determine whether the fiber optic must be replaced. Contact Coherent Service if further guidance is needed.

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Alternative Cleaning Procedure

As an alternative to the cleanroom swab procedure, use the following procedure with lens tissue and a hemostat:

1. With one hand on each end of the lens tissue, fold the tissue in half (width wise), three times. Do not touch any part of the lens tissue that will make contact with the fiber optic surface. See Figure 6-13.

2. Use a hemostat to fold the tissue in half, lengthwise. Do not touch any part of the lens tissue that will be used to clean the fiber optic surface. See Figure 6-14.

3. Attach a hemostat to the lens tissue as shown in Figure 6-15.

Figure 6-13. Folded Lens Tissue (Width Wise)

Figure 6-14. Folded Lens Tissue (Lengthwise)

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Figure 6-15. Hemostat Attached to Properly Folded Lens Tissue

4. Using a medicine dropper, put two drops of Methanol on the lens tissue.

5. Vigorously shake off excess Methanol from the folded tissue to prevent Methanol residue.

Only the lens tissue should make contact with the fiber optic surface. Do not allow the hemostat to touch the fiber surface.

6. Holding the fiber vertically so the lens surface points to the ceiling, carefully place the base of the wet side of the folded tissue against the fiber optic surface, taking care not to touch the fiber optic with the hemostat. See Figure 6-16.

7. Drag the folded tissue across the fiber optic surface in a single stroke. Do not drag the swab back and forth.

8. Repeat Step 7 using the other side of the folded tissue.

9. Re-check the fiber using the fiberscope. If imperfections remain, repeat the procedure using a new lens tissue.

10. If imperfections still remain, compare the image in the fiberscope with Figure 6-19 and determine whether the fiber optic must be replaced. Contact Coherent Service if further guidance is needed.

If the fiber surface is now ideal or complies with the guidelines as illustrated in Figure 6-19 on page 6-39, immediately install the fiber optic into the FAP-I/FAP-B.

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Figure 6-16. Placement and Movement of the Folded Tissue Against the Fiber Optic Surface

Examples of Good and Bad Fibers

Figure 6-17 shows an image of the ideal fiber optic surface that can be used successfully in the FAP-I/FAP-B assembly through a fiberscope. Figure 6-18 shows images of fibers through a fiberscope with imperfections that can impair the function of the assembly. The image on the left is clearly a damaged fiber. Severely damaged fibers must not be used in the FAP-I/FAP-B assembly or permanent and severe damage to the assembly will occur.

The image on the right shows a fiber that is questionable. If the power output is acceptable, then the fiber can be used with little concern for damaging the assembly. However, if the power output is unstable or not up to acceptable standards, the fiber must be considered damaged and must not be used.

Figure 6-19 illustrates further criteria for accepting or rejecting a fiber because of damage. Note that the views shown do not represent the entire surface of the fiber optic. Much of the surface is the metal connector and only the 800-micron core is the actual optical fiber.

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Core

Figure 6-17. Good Fiber

Cladding

Core

Cladding

Bad Fiber (Burned) Questionable Fiber

Figure 6-18. Bad or Questionable Fibers

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Buffer

Maintenance and Service

Cladding

Core

IDEAL FIBER

Chipped

Fibers

Accept < 3

Particles

Under Coating

ACCEPTABLE IMPERFECTIONS

Cracked

Fibers

Particles

Outside

Core

>3 Core

Scratches

Scratch

Across Core

Large

Burn mark

Contamination

CRITERIA FOR REJECTION

Figure 6-19. Guidelines for Fiber Optic Inspection

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LBO Temperature Optimization

The conversion efficiency of the LBO frequency doubler is heavily dependent upon temperature. A temperature change of 1°C can reduce the doubling efficiency by more than 50%. To compensate for the reduced efficiency, the laser will use more current to produce the desired 532 nm output. This will reduce the lifetime of the diodes.

As a solution to this potential problem, the Verdi V-2/V-5/V-6 software contains a menu routine which will perform a LBO temperature optimization automatically to maximize the conversion efficiency of the doubler. The LBO Optimization routine should run when diode current is observed to be 10% greater than baseline values.

Note that the shutter is active during the LBO optimization. Because laser power will change while the routine executes, Coherent recommends the shutter remains closed throughout the process.

To find an accurate LBO setpoint temperature, set the output power level as close to maximum power (depending on system type) as possible. The routine is designed such that it will not run if the laser power level is less than 80% of the specified maximum power.

Performing the Optimization

Once the routine is complete, the system will display “LBO optimized” and return the laser to “Light Regulation” mode at the preset power level.

1. Turn the Verdi on at the maximum power level. Record the LBO setpoint temperature.

2. Scroll to the LBO Optimization submenu and select the LBO optimization routine. LBO optimization requires up to 45 minutes to run.

3. Once the routine is complete, record the LBO temperature as the new baseline value in the system weekly log book.

During optimization, the LBO temperature will increase and decrease with the software recording the Verdi output power at each LBO temperature. (This routine is performed with a constant diode current.)

Optimum LBO temperature will be determined based on the Verdi Output Power vs. LBO Temperature curve. The new temperature will be stored as the LBO temperature set point.

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LBO Error Message

Fuse Replacement

If the system is not able to determine an optimum LBO temperature the message “TLBO < 2°C Temperature not changed” will be displayed. If this should occur, contact your local Coherent Service representative.

Criteria for Replacement

Defective fuse per troubleshooting Charts 1 and 4.

Do not turn the power switch on the rear panel to the OFF position or disconnect the AC power input until the LBO cool down cycle is complete.

1. Perform the procedure in paragraph titled, “Turn-off (Complete Shut-down)” on page 4-5. The associated cool-down cycle will take approximately 30 minutes. The front panel display will indicate when the cool-down cycle is complete.

2. Turn the power switch on the power supply rear panel to the OFF position and disconnect the power cord from facility power.

A fuse that fails repeatedly is an indication of a more serious problem. In this case, the system should be returned to the factory. If the laser system or components are being returned directly to Coherent, an RMA (Return Material Authorization) number is required. Contact Coherent or an authorized representative.

3. The location of the fuse is shown on Figure 4-2 on page 4-8. Insert a small straight-slotted screwdriver and twist counter-clockwise to remove the fuse holder.

4. Replace the fuse with an appropriate fuse and reinstall the fuse holder.

5. Connect the power supply power cord to facility power.

6. Perform the procedure in paragraph titled, “Turn-on (Cold-Start)” on page 4-2.

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Verification of Successful Installation

7. The AC ON indicator on the power supply front panel will light.

Battery Replacement

Preliminary Steps and Data

The backup battery in the laser system power supply must be replaced as soon as possible after the fault message “Battery Requires Service” is displayed on the power supply front panel. Failure to do so may result in damage to the system when coupled with a loss in AC power.

Do not turn the power switch on the rear panel to the OFF position or disconnect the AC power input until the LBO cool down cycle is complete.

With AC power off, the power supply must be plugged in at least every 6 months to allow the battery to charge. Otherwise, permanent charging capacity loss may occur.

1. With the keyswitch set to the ON position and the system in “Light Control” operation, set the laser to its specification output power.

2. Record the following system data from the Temperature Set Points submenu. See menu titled, “Temperature Set Points” on page 4-15:

a. LBO temperature set point

b. Vanadate temperature set point

c. Etalon temperature set point

d. Diode #1 temperature set point

3. Record the following system data from the Diode Parameters Screen submenu. See menu titled, “Diode Parameters Screen” on page 4-16

a. Diode #1 current (software value).

4. Perform the procedure titled, “Turn-off (Complete Shut-down)” on page 4-5. The associated cool-down cycle

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