HP LST3421A-AP, LST2425B-T-AP, LST2425A-T-AP, LST2425A-B-AP, LST3421B-AP Datasheet

Coaxial Pigtailed Laser Module

Preliminary Technical Data

LST2425X, LST3421X

Features

• Compact Coaxial Package

• Strained Multi Quantum
Well Distributed Feedback
(DFB) Laser Chip

• Low Thresholds Current and
Operating Currents

• Wide Operating Tempera­ture -40°C to +85°C

• Excellent Wavelength
Stability with Temperature
~0.1 nm/°C

• Narrow Line Width
<1 nm @ -20 dB

• Side Mode Suppression
Ratio >-30 dB

• Modulation Capability up to
622 Mb/s

• Convenient Variety of
Pinout and Mounting Flange
Options

Applications

• Telecommunications

• Fiber in the Loop

• Inter/Intra Office

• SONET/SDH

• Datacommunications

• Switches

Description

Products in the LST242X family
are compact coaxial pigtailed
DFB laser transmitters, operating
in the 1300 nm wavelength
region and coupling light to
single mode fiber. They are
designed for use in short,
medium and long distance
networks with bit rates up to
622 Mb/s.

The device features a high
reliability SMQW-DFB laser diode
and rear facet monitor photo­diode. These are electrically
connected to four pins in an
industry-standard configuration.

Environmental performance is
designed to be compatible with
the requirements of Bellcore’s
TA-NWT-000983 document.

Options within the LST242X
family offer pinouts and pin
rotational orientations designed
to match existing products
available on the market. We also
offer a comprehensive range of
alternative mounting flanges
including a dual in line option.

If the specific arrangement or
performance you require is not
listed, please contact your local
representative as our highly
flexible design and manufacturing
processes allow both physical and
electro-optical customization to
meet your needs.

Preliminary Product Disclaimer

This preliminary data sheet is provided to assist you in the evaluation of engineering samples of the product which is under development
and targeted for release during 1997. Until Hewlett-Packard releases this product for general sales, HP reserves the right to alter prices,
specifications, features, capabilities, function, manufacturing release dates, and even general availability of the product at any time.

Laser Safety Warning

This device is a Class IIIb (3b) Laser Product. It may emit invisible laser radiation if operated with the fiber pigtail disconnected. To avoid
possible eye damage do not look into an unconnected fiber pigtail during laser operation. Do not exceed specified operating limits.

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Absolute Maximum Ratings

Absolute limiting (maximum) ratings mean that no catastrophic damage will occur if the product is subjected to these ratings for short periods,
provided that each limiting parameter is in isolation and all other parameters have values within the performance specification. It should not be
assumed that limiting values of more than one parameter can be applied to the product at the same time.

Limits

Parameter Symbol Test Condition Min. Max. Units

Laser Forward Current If DC 120 mA
Laser Reverse Voltage Vlr DC 2 V
Photodiode Reverse Voltage Vr DC 20 V
Photodiode Forward Current Ipf DC 1 mA
Operating Temperature A Tc Temperature measured at case –40 +85 °C

B 0 +70 °C

Storage Temperature Ts –40 +85 °C
Relative Humidity RH noncondensing %RH
Fiber Pull Strength Three times; 10 sec. 10 N
Mechanical Shock MIL-STD-883D, Method 2002, 500 G

Condition A

Vibration MIL-STD-883D, Method 2007, 20 G

Condition A

Performance Specifications

LST242X

LST3421

Parameter Symbol Test Condition Min. Max. Units

LASER CW, over operating temperature

range, Po, as noted below unless
otherwise stated and –20 dB ORL

Rated Optical Power Po Tc = ranges specified above, CW 2 mW
Threshold Current Ith Tc = +25°C415mA
Threshold Current Ith Over operating temperature range 2 40 mA
Coupled Power in “Off” State Pth If = Ith – 2 mA 0 10 µW
Drive Current above Ith, Id Tc = +25°C 12.5 25 mA

for Im = Im (Po, +25°C)
Forward Voltage Vf 1.6 V

Center Wavelength λ Over operating temperature range 1280 1335 nm
Wavelength/Temperature ∆λ/∆T 0.1 nm/°C

Coefficient
Spectral Width σ At –20 dB 1 nm
Side Mode Suppression Ratio SMSR +30 dB
Rise and Fall Time τ 10-90%, Ith to Po 0.5 ns
MONITOR PHOTODIODE Tc = +25°C, Vr = 5 V,

Photocurrent Im 50 1000 µA
Dark Current Id Po = 0 µW20nA
Capacitance C 1 MHz 10 pF
Tracking Error ∆R Im = Im (Po, +25°C) –1 1 dB

Over operating temperature range - 40 mA

Po = Rated Power

Tc + –40°C to + 85°C

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