AGERE D2570H912, D2570H911, D2570H910, D2570H909, D2570H908 Datasheet

D2570, D2526, D2555 Wa velength-Selected
Direct Modulated Isolated DFB Laser Module

Applications

■

Three direct-modulated DWDM families available
to meet a number of OC-48/STM-16 applications:
—Extended reach (100 km)
—Very long reach (170 km)
—Metro DWDM
—Digital video

Product Codes

Data Sheet, Rev. 3

July 2001

The 1.5 µm D2570, D2526G, and D2555 Laser Modules are
available in a 14-pin, hermetic, butterfly package.

Features

■

ITU wavelengths available from

1528.77 nm —1610.06 nm

■

SONET/SDH compatible up to OC-48/STM-16

■

Temperature tunable for precise wavelength
selection

■

Integrated optical isolator

■

High-performance, multiquantum well (MQW)
distributed-feedback (DFB) laser

■

Industry-standard, 14-pin butterfly package

■

Characterized at 2.488 Gbits/s (NRZ)

■

InGaAs, PIN photodetector back-facet monitor

■

Low threshold current

■

High-reliability, hermetic packaging

■

Excellent long-term wavelength stability can elimi­nate the need for external wavelength locker

■

Qualified to meet the intent of

gies

* 468

*

Telcordia Technologies

Inc.

is a trademark of Telcordia Technologies,

Telcordia Technolo-

Product

Code

Peak

Power

Dispersion

Performance

D2570H 10 mW 1800 ps/nm (100 km)
D2526G 2 mW 1800 ps/nm (100 km)
D2555G 2 mW 3000 ps/nm (170 km)

Description

The Direct Modulated Isolated DFB Laser Module
contains an internally cooled, InGaAs, MQW, distrib­uted-feedback (DFB) laser designed for 1.5 µm appli­cations. The f ollowing three d irect-modulation D WDM
product families have been established to meet vari­ous OC-48/STM-16 system applications:

■

D2526-type: designed to be used in OC-48/
STM-16 (2.488 Gbits/s) for extended reach, dense
WDM applications (1800 ps/nm). The wavelength
of the laser can be temperature-tuned for precise
wavelength selection by adjusting the temperature
of the internal thermoelectric cooler.

■

D2555-type: high-perf ormance device designe d for
very low dispersion; used in fi ber sp ans exceeding
170 km (3000 ps/nm).

■

D2570-type: high-power, direct-modulated laser
eliminates the need for optic al amplifier s in DWDM
many applications.

D2570, D2526G, D2555 Wavelength-Selected Data Sheet, Rev. 3
Direct Modulated Isolated DFB Laser Module July 2001

Description

(continued)

Controlled Feedback

The module contains an internal optical isolator that
suppresses optical fee dbac k in l aser-based, fi ber-opt ic
systems. Light reflected back to the laser is attenuated
a minimum of 30 dB.

Controlled Temperature

An integral thermoelectric cooler (TEC) provides stab le
thermal characteristics. The TEC allows for heating
and cooling of the laser chip to mai ntain a te mper ature
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 wi th external circuitry to
control the laser chip temperature.

Controlled Power

An internal, InGaAs, PIN photodiode functions as the
back-f a ce t moni tor. 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 arr angement 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, which separates the dc-bias path from the RF
input. The RF input has a nominal 25 Ω impedance.

The laser module is equipped with

SMF-28

The fiber has a 900 µm tight buffer jacket. Var ious con­nectors and pigtail lengths are available.

*

type fiber .

Pin Information

Pin Name

1 Thermistor
2 Thermistor
3 Laser dc Bias (Cathode) (–)
4 Back-facet Monitor Anode (–)
5 Back-facet Monitor Cathode (+)
6 Thermoelectric Cooler (+)*
7 Thermoelectric Cooler (–)
8 Case Ground

9 Case Ground
10 Case Ground
11 Laser Anode (+)
12 RF Laser Input Cathode (–)
13 Laser Anode (+)
14 Case Ground

* A positive current through the thermoelectric heat pump cools the

laser.

† Both leads should be grounded for optim um performance.

76 54 32 1

++– –

–

TEC

PACKAGE

GROUNDS

8 9 10 11 12 13

Top view.

160 nH

+–+

L1

R1
20

Ω

TH

10 k

Ω

ISOLATOR

NC

14

Figure 1. Circuit Schematic

†

†

†

1-567F.b

Agere Systems’ optoelectronic components are being
qualified to rigorous internal standards that are consis­tent with
design and manufacturing operations are

Telcordia Technologies

TR-NWT-000468. All

ISO

* 9001
certified. The module is being fully qualified for central
office applications.

*

ISO

is a registered trademark of The International Organization f or

Standardization.

†

SMF-28

is a trademark of Corning Inc.

2 Agere Systems Inc.

Data Sheet, Rev . 3 D2570, D2526G, D2555 Wavelength-Selected

1-532

Note: Dimensions are in inches and (millimeters).

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)

July 2001 Direct Modulated Isolated DFB Laser Module

Absolute Maximum Rat ings

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 performance characteristics of the data sheet. Exposure to absolute maximum ratings for
extended periods can adversely affect device reliability.

Parameter Symbol Min Max Unit

Laser Reverse Voltage V
dc Forward Current I
Operating Case Temperature Range T
Storage Case Temperature Range* T
Photodiode Reverse Voltage V
Photodiode Forward Current I

* Does not apply to shipping container.

RLMAX

FLMAX

C

stg

RPDMAX

FPDMAX

—2V

—150mA
–40 70 °C
–40 85 °C

—10V

—2mA

Handling Precautions

Power Sequencing

To avoid the possibility of damage to the laser module
from power supply switching transients, follow this turn­on 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).

Mounting Instructions

The minimum fiber bend radius is 1.23 in (31.25 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 surf ace flatness
must be better than 0.001 in. (25.4 µm). Using ther­mal conductive grease is optional ; how ever, thermal
performance can be improved by up to 5% if con­ductive grease is app lied betwe en 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.

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 k¾, 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:

Parameter Value Unit

Human-body Model >400 V

Agere Systems Inc. 3

Figure 2. Fillister Head Screw

D2570, D2526G, D2555 Wavelength-Selected Data Sheet, Rev. 3
Direct Modulated Isolated DFB Laser Module July 2001

D2526 Characteristics

Minimum and maximum values are testing requirements. Typical values are characteristics of the device and are
the result of engineering e v aluations . Typical values are for inf ormation purposes only and are not part of the testing
requirements.

Table 1. Electrical Characteristics (at 25 °C laser temperature)

Parameter Symbol Test Conditions Min Typ Max Unit

Slope Efficiency η L
Threshold Current I
Laser Forward Voltage V
Laser Submount Temperature T
Monitor Reverse-bias Voltage* V
Monitor Current I
Monitor Dark Current I
Input Impedance Z
Thermistor Current I
Resistance Ratio

†

Thermistor Resistance R
TEC Current I
TEC Voltage V

TH

LF

LASER

RMON

RMON

D
IN

TC

— — 9.1 — 9.6 —

TH

TEC

TEC

TEC Capacity ∆TT

* Standard operating condition is 5.0 V reverse bias.
† Ratio of thermistor resistance at 0 °C to thermistor resistance at 50 °C.

F

= 2 mW (CW) 0.06 0.09 0.13 mW/mA

——1430mA

LF = 2 mW (CW) — 1.3 1.8 V

—20—30°C
—3510V

POL = 1 mW (CW) 0.1 0.3 1.5 mA

IF = 0, V

RMON

= 5 V — 0.01 0.1 µA
——25—Ω
— 10 — 100 µA

TL = 25 °C 9.5 — 10.5 kΩ

TL = 25 °C, TC = 70 °C — 0.6 1.0 A

TL = 25 °C, TC = 70°C — 1.3 2.0 V

C

= 70 °C — — 50 °C

Table 2. Optical Characteristics (at 25 °C laser temperature)

Parameter Symbol Test Conditions Min Typ Max Unit

Peak Optical Output Power P
Center Wavelength

(See Table 10.)

Line Width (3 dB full width) ∆λ Modulated at 2.5 Gbits/s

PEAK

λcT

—2.0——mW

L

= 25 °C

CW wavelength

1528.77 — 1610.06 nm

—210MHz

at rated power

Side-mode Suppression Ratio SMSR CW 30 — — dB

C

Optical Isolation — T
Wavelength Drift (EOL) ∆λ Tested over

= 0 °C to 70 °C 30 — — dB

——±0.1nm

25-year lifetime

Center Wavelength Drift with

C

/∆T

0 °C ≤ TC ≤ 70 °C — — 1 pm/°C

C

∆λ

Case Temperature

Wavelength Temperature Tuning

— — — 0.095 — nm/°C

Coefficient

C

Tracking Error — T

= –20 °C/25 °C/70 °C — — 1 dB

Table 3. Dispersion Performance

Parameter Symbol

Test

Conditions

Min Typ Max Unit

Dispersion Penalty for Extended Reach DP 1800 ps/nm — — 2.0 dB

4 Agere Systems Inc.