Data Sheet, Rev. 2
July 2001
Wavelength-Selected High-Power D2587P-Type (with
Wavelength Locker)/D2547P-Type Isolated DFB Laser Modules
Applications
s
Telecommunications:
— Dense WDM
— SONET/SDH OC-192/STM-64
— Extended and ultralong reach
— Undersea systems
Digital video
s
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.
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) appli-
cations.
Features
s
High-performance, multiquantum-well (MQW),
distributed-feedback (DFB) laser
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
High optical power (20 mW, CW)
Hermetic, 14-pin package
s
s
s
s
s
s
Wavelength-Selected, High-Power D2587P-Type (with Wavelength
Locker)/D2547P-Type Isolated DFB Laser Modules
Data Sheet, Rev. 2
July 2001
Description
(continued)
Principles of Operation (Controlled Wave-
length)
The single-channel, wavelength-selected DFB (ILM) pack-
age contains internal wavelength-discriminating optics, i.e.,
two etalons and associated photodiodes. The output con-
sists of analog signals suitable for controlling the electrical
current of the thermoelectric cooler (TEC) and the DFB
laser.
Agere Systems’ optoelectronic components are being qual-
ified to rigorous internal standards that are consistent with
Telcordia Technologies
†
TR-NWT-000468. All design and
manufacturing operations are
ISO
§
9001 certified. The
module is being fully qualified for central office applications.
*
Fujikura
is a registered trademark of Fujikura Ltd.
†
Telcordia Technologies
is a trademark of Telcordia Technologies
Inc.
§
ISO
is a registered trademark of The International Organization for
Standardization.
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.
CORE
STRESS ROD
PRINCIPLE POLARIZATION
AXIS
CLADDING
INNER COATING
(SILICON & ACRYLATE)
OUTER COATING
1-771(C).a
Controlled Temperature
An integral 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
–25 °C to +70 °C. The laser temperature is monitored by
the internal thermistor, which can be used with external cir-
cuitry to control the laser chip temperature.
Figure 1. Polarization-Maintaining Fiber
Pin Information
Table 1. Pin Descriptions
Pin
1
2
3
4
5
D2587P-Type
Thermistor
Thermistor
Laser dc Bias
(Cathode) (–)
Back-facet Monitor
Anode (–)
Back-facet Monitor
Cathode (+)
TEC (+)
1
TEC (–)
1
Case Ground
λ
Photodiode 2 Anode
λ
Photodiode 1 Anode
Laser Anode (+)
2
RF Laser Input
Cathode (–)
Laser Anode (+)
2
NC
D2547P-Type
Thermistor
Thermistor
Laser dc Bias
(Cathode) (–)
Back-facet Monitor
Anode (–)
Back-facet Monitor
Cathode (+)
TEC (+)
1
TEC (–)
1
Case Ground
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
Ω
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 Agere Systems Inc. lithium
niobate modulators. It has a mode field diameter of
10.5
µm,
a cladding diameter of 125
µm
±3
µm,
and a
loose tube jacketed fiber 900
µm
in diameter. Figure 1
shows the orientation of polarization in the fiber.
6
7
8
9
10
11
12
13
14
Case Ground
Case Ground
Laser Anode (+)
2
RF Laser Input
Cathode (–)
Laser Anode (+)
2
Case Ground
1. A positive current through the thermoelectric heat pump cools the
laser.
2. Both leads should be grounded for optimum performance.
2
Agere Systems Inc.
Data Sheet, Rev. 2
July 2001
Wavelength-Selected, High-Power D2587P-Type (with Wavelength
Locker)/D2547P-Type Isolated DFB Laser Modules
Description
(continued)
7
–
6
+
5
+
4
–
L1
140 nH
TEC
3
–
TH
10 kΩ
2
1
PACKAGE
GROUNDS
+
8
9
10
11
R1
20
Ω
–
12
ISOLATOR
NC
+
13
14
1-567
Top view.
Figure 2. D2547P Circuit Schematic
7
6
5
4
3
2
1
TEC
RFC
PD
POWER
R
TH
PM FIBER PIGTAIL
PD
WAVE
PD
WAVE
LD
R
RF
8
9
10
11
12
13
14
1-1130(F)
Figure 3. D2587P Circuit Schematic
Block Diagram
LASER MODULE
DUAL
ETALON
DFB
SILICON SUBMOUNT
THERMISTOR
THERMOELECTRIC COOLER
ISOLATOR AND
FIBER COUPLING
OPTICS
A TO D
CONVERTER
EEPROM
SUGGESTED
ELECTRONICS MODULE (CUSTOMER SUPPLIED)
MICROPROCESSOR
D TO A
CONVERTER
VOLTAGE PROPORTIONAL TO WAVELENGTH
VOLTAGE PROPORTIONAL TO OPTICAL POWER
VOLTAGE PROPORTIONAL TO TEMPERATURE
1-1129(F)
Agere Systems Inc.
3
Wavelength-Selected, High-Power D2587P-Type (with Wavelength
Locker)/D2547P-Type Isolated DFB Laser Modules
Data Sheet, Rev. 2
July 2001
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.
Parameter
Laser Reverse Voltage
dc Forward Current
Operating Case Temperature Range
Storage Case Temperature Range*
Photodiode Reverse Voltage
Photodiode Forward Current
* Does not apply to shipping container.
Symbol
V
RLMAX
I
FLMAX
T
C
T
stg
V
RPDMAX
I
FPDMAX
Min
—
—
–25
–40
—
—
Max
2
225
70
70
10
2
Unit
V
mA
°C
°C
V
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.
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 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.
0.062 (1.58)
0.031 (0.79)
0.140
(3.56)
0.129 (3.28) R
0.041 (1.04)
1-532(C)
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).
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 com-
parison purposes. The HBM ESD threshold presented
here was obtained using these circuit parameters:
Parameter
Human-body Model
Value
>400
Unit
V
0.118
(3.00)
0.086
(2.18)
Note: Dimensions are in inches and (millimeters).
Figure 4. Fillister Head Screw
4
Agere Systems Inc.
Data Sheet, Rev. 2
July 2001
Wavelength-Selected, High-Power D2587P-Type (with Wavelength
Locker)/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.
Table 2. D2587-Type Electrical Characteristics
(at 25 °C laser temperature)
Parameter
Threshold Current
Drive Current
Laser Forward Voltage
Monitor Reverse-bias Voltage*
Monitor Current:
Back-facet Monitor
λ
Photodiode 1
λ
Photodiode 2
Monitor Dark Current
Input Impedance
Filter Slope
Frequency Capture Range
Symbol
I
TH
—
V
LF
V
RMON
I
RMON
I
λPD1
I
λPD2
I
D
Z
IN
—
—
I
F
= 0, V
RMON
= 5 V
—
—
Measured from
λ
ITU
toward increasing
λ
and
decreasing
λ
—
—
T
L
= 25 °C
—
T
L
= 25 °C, T
C
= 70 °C
T
L
= 25 °C, T
C
= 70 °C
T
C
= 70 °C
Test Conditions
—
L
F
= 20 mW
L
F
= 20 mW (CW)
—
P
O
= 20 mW (CW)
0.003
0.003
0.003
—
—
0.5
15
—
—
—
0.01
25
—
—
0.06
0.06
0.06
0.1
—
8
—
mA
mA
mA
µA
Ω
/nm
GHz
Min
—
—
—
3
Typ
15
—
2
5
Max
40
165
2.5
10
Unit
mA
mA
V
V
Thermistor Current
Resistance Ratio
†
Thermistor Resistance
Laser Submount Temperature
TEC Current
TEC Voltage
TEC Capacity
I
TC
—
R
TH
T
SET
I
TEC
V
TEC
∆T
10
9.1
9.5
20
—
—
—
—
9.6
—
—
—
—
100
10.1
10.5
35
1.7
2.8
50
µA
—
kΩ
°C
A
V
°C
* Standard operating condition is 5.0 V reverse bias.
† Ratio of thermistor resistance at 0 °C to thermistor resistance at 50 °C.
Table 3. D2587-Type Optical Characteristics
(at 25 °C laser temperature)
Parameter
Peak Optical Output Power
Center Wavelength*
(See Ordering Information, page 9.)
Line Width (3 dB full width)
Side-mode Suppression Ratio
Relative Intensity Noise
Optical Isolation
Optical Polarization Extinction Ratio
†
FM Efficiency
Wavelength Drift (EOL)
Symbol
P
P
λ
C
∆λ
SMSR
RIN
—
—
FM
∆λ
C
Test Conditions
—
T
L
= T
SET
λ
C
=
λ
ITU
± 0.1 nm
CW, P
F
= 20.0 mW
CW
CW, P
F
= 20 mW
200 MHz < f < 10 GHz
T
C
= 0 °C to 75 °C
0 °C to 75 °C
f
MOD
= 30 kHz,
P
F
= 20 mW
Tested over
25-year lifetime
Min
20.0
1528.77
—
35
—
30
20
—
—
Typ
—
—
2
45
—
—
—
100
—
Max
—
1610.06
10
—
–135
—
—
—
±2.5
Unit
mW
nm
MHz
dB
dB/Hz
dB
dB
MHz/mA
GHz
* Custom wavelengths available.
† The
ST
®
ferrule key is not aligned to slow axis of fiber. Connector is intended for testing purposes only.
Agere Systems Inc.
5
