Telecommunications:
— Dense WDM
— SONET/SDH OC-192/STM-64
— Extended and ultralong reach
— Undersea systems
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Digital video
Data Sheet, Rev. 2
July 2001
Featuring wavelength selection and locking capabilities, the
D2587P Laser Module is ideally suited for use with external
lithium niobate modulators, and in high-power (20 mW) applications.
D2587P-Type is offered on 50 GHz ITU grid
wavelengths ranging from 1528.77 nm—
1610.06 nm
■
D2547P-Type is offered on 100 GHz ITU grid
wavelengths ranging from 1528.77 nm—
1610.06 nm
■
Polarization-maintaining fiber pigtail
■
For use with lithium niobate modulators
Description
The D2587P-Type DFB laser module is designed for
use with an external lithium niobate modulator and
also in applications where high power (20 mW) is
required.
The use of an internal wavelength locker greatly
enhances long-term reliability and reduces chirp and
mode dispersion when used in conjunction with LN
modulators at OC-192 data rates.
A companion device, the D2547P high-power DFB
laser module, is also designed for use with a lithium
niobate external modulator, but without the use of an
internal wavelength locker.
The single-channel, wavelength-selected DFB (ILM) package contains internal wavelength-disc riminating optics , i.e . ,
two etalons and associated photodiodes. The output consists of analog signals suitable for controlling the electrical
current of the thermoelectric cooler (TEC) and the DFB
laser.
Controlled Feedback
The module contains an internal optical isolator that suppresses optical feed back in laser-based, fiber-optic systems. Light reflected back to the laser is attenuated a
minimum of 30 dB.
Controlled Temperature
An integral TEC provides stable thermal characteristics.
The TEC allows for heat ing and cooling of the laser chip to
maintain a temperature of 25 °C for ca se temperatures fro m
–25 °C to +70 °C. The laser temperature is monitored by
the internal thermistor, which can be used with external circuitry to control the laser chip temperature.
Agere Systems’ optoelectronic components are being qualified to rigorous internal standards that are consistent with
Telcordia Technologies
manufacturing oper ations are
†
TR-NWT-000468. All design and
§
9001 certified. The
ISO
module is being fully qualified for central office applications.
*
†
§
is a registered trademark of Fujikura Ltd.
Fujikura
Telcordia Technologies
Inc.
is a registered trademark of The International Organization for
ISO
Standardization.
is a trademark of Telcordia Technologies
CORE
STRESS ROD
PRINCIPLE POLARIZATION
AXIS
CLADDING
INNER COATING
(SILICON & ACRYLATE)
OUTER COAT ING
1-771(C).a
Figure 1. Polarization-Maintaining Fiber
Pin Information
Table 1. Pin Descriptions
Controlled Power
An internal, InGaAs, PIN photodiode functions as the backfacet monitor. The photodiode monitors emission from the
rear facet of the laser and, when used in conjun ct io n with
control circuitry, can control optic al power launched into the
fiber. Normally, this configuration is used in a feedbac k
arrangement to maintain consistent laser output power.
Standard Package
The laser module is fabricated in a 14-pin, hermetic, metal/
ceramic butterfly package that incorporates a bias tee that
separates the dc-bias p ath from the RF input. The RF input
has a nominal 25 Ω impedance.
The laser module is equipped with
Fujikura
maintaining fiber (PMF). The fiber is PANDA type an d is the
same fiber that is used on the Agere Systems Inc. lithium
niobate modulators. It has a mode field diameter of
10.5 µm, a cladding diameter of 125µm ±3 µm, and a
loose tube jacketed fiber 900 µm in diameter. Figure 1
shows the orientation of polarization in the fiber.
* polarization-
Pin D2587P-TypeD2547P-Type
1 ThermistorThermistor
2ThermistorThermistor
3Laser dc Bias
(Cathode) (–)
4Back-facet Monitor
Anode (–)
5Back-facet Monitor
Cathode (+)
6TEC (+)
7TEC (–)
1
1
Laser dc Bias
(Cathode) (–)
Back-facet Monitor
Anode (–)
Back-facet Monitor
Cathode (+)
TEC (+)
TEC (–)
1
1
8Case GroundCase Ground
9
Photodiode 2 Anode
λ
10λ Photodiode 1 Anode
11Laser Anode (+)
2
12RF Laser Input
Cathode (–)
13Laser Anode (+)
2
14NC
1.A positive current through the thermoelectric heat pump cools the
laser.
2.Both leads should be grounded for optimum performance.
Case Ground
Case Ground
Laser Anode (+)
RF Laser Input
Cathode (–)
Laser Anode (+)
Case Ground
2
2
22
Agere Systems Inc.
Data Sheet, Rev. 2Wavelength-Selected, High-Power D2587P-Type (with Wavelength
July 2001Locker)/D2547P-Type Isolated DFB Laser Modules
Description
(continued)
76 54 32 1
–+ +– –
L1
TEC
PACKAGE
GROUNDS
8910111213
140 nH
+–+
R1
20
TH
10 k
ISOLATOR
Ω
Ω
NC
14
1-567
Top view .
Figure 2. D2547P Circuit Schematic
7654321
R
TEC
PD
WAVE
PD
WAVE
PD
POWER
LD
RFC
R
RF
TH
PM FIBER PIGTAIL
Block Diagram
A TO D
CONVERTER
MICROPROCESSOR
891011121314
Figure 3. D2587P Circuit Schematic
DUAL
ETALON
THERMISTOR
EEPROM
D TO A
CONVERTER
THERMOELECTRIC COOLER
SUGGESTED
ELECTRONICS MODULE (CUSTOMER SUPPLIED)
VOLTAGE PROPORTIONAL TO WAVELENGTH
VOLTAGE PROPORTIONAL TO OPTICAL POWER
VOLTAGE PROPORTIONAL TO TEMPERATURE
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess
of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for extended
periods can adversely affect device reliability.
ParameterSymbolMinMaxUnit
Laser Reverse VoltageV
dc Forward Current I
Operating Case Temperature Range T
Storage Case Temperature Range*T
Photodiode Reverse Vo lta geV
Photodiode Forward CurrentI
* Does not apply to shipping container.
RLMAX
FLMAX
C
stg
RPDMAX
FPDMAX
—2V
—225mA
–2570°C
–4070°C
—10V
—2mA
Handling Precautions
Power Sequencing
To avoid the possibility of damage to the laser module
from power supply switching transients, follow this
turn-on sequence:
1. All ground connections
2. Most negative supply
3. Most positive supply
4. All remaining connections
Reverse the order for the proper turn-off sequence.
Electrostatic Discharge
CAUTION: This device is susceptible to damage as
a result of electrostatic discharge. Take
proper precautions during both handling and testing. Follow guidelines
such as JEDEC Publication No. 108-A
(Dec. 1988).
Agere Systems employs a human-body model (HBM)
for ESD-susceptibility testing and protection-design
evaluation. ESD voltage thresholds are dependent on
the critical parameters used to define the model. A
standard HBM (resistance = 1.5 kΩ, capacitance = 100
pF) is widely used and, therefore, can be used for comparison purposes. The HBM ESD threshold presented
here was obtained using these circuit parameters:
Mounting Instructions
The minimum fiber bend radius is 1.0 in. (25.4 mm)
To avoid degradation in performance, mount the mod-
ule on the board as follows:
1. Place the bottom flange of the module on a flat heat
sink at least 0.5 in. x 1.180 in. (12.7 mm x 30 mm) in
size. The surface finish of the heat sink should be
better than 32 µin. (0.8 µm), and the surface flatness
must be better than 0.001 in. (25.4 µm). Using thermal conductive grease is optional; however, thermal
performance can be improved by up to 5% if conductive grease is applied between the bottom flange and
the heat sink.
2. Mount four #2-56 screws with Fillister heads
(M2-3 mm) at the four screw hole locations (see Outline Diagram). The Fillister head diameter must not
exceed 0.140 in. (3.55 mm). Do not apply more than
1 in.-lb. of torque to the screws.
0.062 (1.58)
0.031 (0.79)
0.140
(3.56)
Note: Dimensions are in inches and (millimeters).
0.118
(3.00)
0.086
(2.18)
0.129 (3.28) R
0.041 (1.04)
1-532(C)
Parameter Value Unit
Human-body Model >400V
4
Figure 4. Fillister Head Screw
Agere Systems Inc.
Data Sheet, Rev. 2Wavelength-Selected, High-Power D2587P-Type (with Wavelength
July 2001Locker)/D2547P-Type Isolated DFB Laser Modules
Characteristics
Minimum and maximum values are testing requirements. Typical values are device characteristics and are results
of engineering evaluations; they are for information purposes only and are not part of the testing requirements.