Wavelength-Selected D2525P
Isolated DFB Laser Module with PMF
Data Sheet, Rev. 2
February 2003
TriQuint Optoelectronics
Features
ITU wavelengths available from
1529.55 nm --1610.06 nm
Integrated optical isolator
High-performance, multiquantum-well (MQW),
distributed-feedback (DFB) laser
Industry-standard, 14-pin butterfly package
Hermetic package
InGaAs, PIN photodetector back-facet monitor
Polarization-maintaining fiber pigtail
For use with lithium niobate modulators
High reliability
Narrow linewidth
High optical power available
Applications
Telecommunications
-- SONET/SDH OC-48/STM-16, OC-192/STM-64
-- Extended and ultralong reach
-- Undersea systems
-- Dense WDM systems
Digital video
Description
The D2525P family of DFB laser modules is designed
to be used with a lithium niobate external modulator
(see Table 5). The laser module features a polariza-
tion-maintaining fiber (PMF) pigtail, enabling it to be
directly connected to a modulator without the need of a
polarization controller. The PMF maintains the polar-
ization of the output light to a consistent orientation.
This allows the D2525P to be used as a CW light
source for systems requiring extremely low chirp such
as undersea or 10 Gb/s systems. The module contains
a multiquantum-well (MQW), distributed-feedback
(DFB) laser. This device nominally has an output
power of 10 mW. The wavelength of the laser can be
temperature-tuned for more precise wavelength selec-
tion by adjusting the temperature of the internal ther-
moelectric cooler.
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The 1.5 m D2525P Laser Module is available in a 14-pin, hermetic,
butterfly package.
Wavelength-Selected D2525P
Data Sheet, Rev. 2
Isolated DFB Laser Module with PMF
February 2003
2
2
For additional information and latest specifications, see our website: www.triquint.com
Description
(continued)
Controlled Feedback
The module contains an internal optical isolator that sup-
presses optical feedback in laser-based, fiber-optic sys-
tems. Light reflected back to the laser is attenuated a
minimum of 30 dB.
Controlled Temperature
An integral thermoelectric cooler (TEC) provides stable
thermal characteristics. The TEC allows for heating and
cooling of the laser chip to maintain a temperature of 25 C
for case temperatures from 40 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.
Controlled Power
An internal, InGaAs, PIN photodiode functions as the back-
facet monitor. The photodiode monitors emission from the
rear facet of the laser and, when used in conjunction with
control circuitry, can control optical power launched into the
fiber. Normally, this configuration is used in a feedback
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 path from the RF input. The RF input
has a nominal 25
impedance.
The laser module is equipped with Fujikura* polarization-
maintaining fiber (PMF). The fiber is PANDA type and is the
same fiber that is used on the TriQuint lithium niobate mod-
ulators. It has a mode field diameter of 10.5
m, a cladding
diameter of 125
m 3 m, and a loose tube jacketed fiber
900
m in diameter. The pigtail is terminated with an ST
ferrule
. Figure 1 shows the orientation of polarization in the
fiber.
TriQuint optoelectronic components are being qualified to
rigorous internal standards that are consistent with Telcor-
dia Technologies
TR-NWT-000468. All design and manu-
facturing operations are ISO
9001 certified. The module is
being fully qualified for central office applications.
* Fujikura is a registered trademark of Fujikura Ltd.
The ST ferrule key is not aligned to slow axis of fiber. Connector is
intended for testing purposes only.
Telcordia Technologies is a trademark of Telcordia Technologies
Inc.
ISO is a registered trademark of The International Organization for
Standardization.
Figure 1. Polarization-Maintaining Fiber
Pin Information
1. A positive current through the thermoelectric heat pump cools the
laser.
2. Both leads should be grounded for optimum performance.
Figure 2. Circuit Schematic
Table 1. Pin Descriptions
Pin Name
1 Thermistor
2
Thermistor
3
Laser dc Bias (Cathode) ()
4
Back-facet Monitor Anode ()
5
Back-facet Monitor Cathode (+)
6
Thermoelectric Cooler (+)
1
7
Thermoelectric Cooler ()
1
8
Case Ground
9
Case Ground
10
Case Ground
11
Laser Anode (+)
2
12
RF Laser Input Cathode ()
13
Laser Anode (+)
2
14
Case Ground
CORE
STRESS ROD
PRINCIPLE POLARIZATION
AXIS
CLADDING
INNER COATING
OUTER COATING
(SILICON & ACRYLATE)
1-567
Top view.
1-567
TEC
L1
160 nH
ISOLATOR
R1
20
PACKAGE
GROUNDS
+
+
+
+
7
6
5
4
3
2
1
8
9
10
11
12
13
TH
10 k
14
1-567.b
Data Sheet, Rev. 2
Wavelength-Selected D2525P
February 2003
Isolated DFB Laser Module with PMF
For additional information and latest specifications, see our website: www.triquint.com
3
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-
lute 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.
* Does not apply to shipping container.
Parameter
Symbol
Min
Max
Unit
Laser Reverse Voltage
V
RLMAX
--
2
V
dc Forward Current
I
FLMAX
--
225
mA
Operating Case Temperature Range
T
C
40
70
C
Storage Case Temperature Range*
T
stg
40
70
C
Photodiode Reverse Voltage
V
RPDMAX
--
10
V
Photodiode Forward Current
I
FPDMAX
--
2
mA
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 han-
dling and testing. Follow guidelines
such as JEDEC Publication No. 108-A
(Dec. 1988).
TriQuint 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 k
, capacitance = 100 pF) is widely
used and, therefore, can be used for comparison pur-
poses.
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
in. (0.8
m), and the surface flatness
must be better than 0.001 in. (25.4
m). Using ther-
mal conductive grease is optional; however, thermal
performance can be improved by up to 5% if conduc-
tive 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 Out-
line 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.
Note: Dimensions are in inches and (millimeters).
Figure 3. Fillister Head Screw
0.118
(3.00)
0.062 (1.58)
0.140
(3.56)
0.031 (0.79)
0.129 (3.28) R
0.086
(2.18)
0.041 (1.04)
1-532(C)
Wavelength-Selected D2525P
Data Sheet, Rev. 2
Isolated DFB Laser Module with PMF
February 2003
4
For additional information and latest specifications, see our website: www.triquint.com
Characteristics
* Standard operating condition is 5.0 V reverse bias.
Ratio of thermistor resistance at 0 C to thermistor resistance at 50 C.
* Custom wavelengths available.
The ST ferrule key is not aligned to slow axis of fiber. Connector is intended for testing purposes only.
Table 2. Electrical Characteristics (at 25 C laser temperature)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Threshold Current
I
TH
--
--
15
35
mA
Drive Current Above Threshold
--
L
F
= 10 mW
--
--
110
mA
Laser Forward Voltage
V
LF
L
F
= 10 mW (CW)
--
1.3
1.8
V
Laser Submount Temperature
T
LASER
--
20
--
30
C
Monitor Reverse-bias Voltage*
V
RMON
--
3
5
10
V
Monitor Current
I
RMON
P
O
= 10 mW (CW)
0.2
--
--
mA
Monitor Dark Current
I
D
I
F
= 0, V
RMON
= 5 V
--
0.01
0.1
A
Input Impedance
Z
IN
--
--
25
--
Thermistor Current
I
TC
--
10
--
100
A
Resistance Ratio
--
--
9.1
9.6
10.1
--
Thermistor Resistance
R
TH
T
L
= 25 C
9.5
--
10.5
k
TEC Current
I
TEC
T
L
= 25 C, T
C
= 70 C
--
--
1.0
A
TEC Voltage
V
TEC
T
L
= 25 C, T
C
= 70 C
--
--
2.0
V
TEC Capacity
T
T
C
= 70 C
--
--
50
C
Table 3. Optical Characteristics (at 25 C laser temperature)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Peak Optical Output Power
P
P
--
10.0
--
--
mW
Center Wavelength*
(See Table 4.)
C
T
L
= 25 C
CW Wavelength
1529.55
--
1610.06
nm
Line Width (3 dB full width)
CW, P
F
= 10.0 mW
--
2
10
MHz
Relative Intensity Noise
RIN
CW, P
F
= 10.0 mW,
200 MHz < f < 10 GHz
--
--
135
dB/Hz
Side-mode Suppression Ratio
SMSR
CW
35
45
--
dB
Optical Isolation
--
T
C
= 0 C to 75 C
30
--
--
dB
Optical Polarization Extinction Ratio
--
0 C to 75 C
20
--
--
dB
Wavelength Drift (EOL)
Tested over 25 yr. lifetime
0.1
nm
Wavelength Drift vs. Case Temperature
--
--
--
--
1
pm/C
Table 4. D2525P Fiber Pigtail and Connector Characteristics
Parameter
Symbol
Description Min
Typ
Max
Unit
Pigtail Length
L
Fujikura PANDA
or equivalent polarization-
maintaining fiber
1.5
--
--
m
Connector Type
--
ST Plug
--
--
--
--
Data Sheet, Rev. 2
Wavelength-Selected D2525P
February 2003
Isolated DFB Laser Module with PMF
For additional information and latest specifications, see our website: www.triquint.com
5
Outline Diagram
Dimensions are in inches and (millimeters). Tolerances are 0.005 in. (0.127 mm).
1-520.h
0.180 (4.56)
HEAT SINK
0.215 (5.45)
0.056 (1.42)
0.030 (0.75)
59.06 (1500.00)
MIN
0.10
(2.5)
0.260 (6.60)
0.215
(5.47)
REF
0.036
(0.91)
PIN 1
0.078 (1.98)
0.100 (2.54) TYP
0.105 (2.67) DIA
TYP (4) PLACES
0.020 (0.51) TYP
0.500 (12.70)
MIN
STRAIN
RELIEF
PIN 14
TRADEMARK, CODE, LASER SERIAL NUMBER,
AND DATE CODE IN APPROX. AREA SHOWN
0.200
(5.08)
~
1.025 (26.04)
0.10 0.002
(2.54 0.051)
0.213 (5.40) TYP
0.500
(12.70)
0.350
(8.89)
0.605
(15.37)
MAX
2.03 (51.6)
0.863 (21.91)
0.575 (14.61)
0.820 (20.83)
0.700 (17.78)
0.365
(9.27)
MAX
1.180 (29.97)
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