Wavelength-Selected D2525P

Data Sheet

Isolated DFB Laser Module with PMF

March 2000

2

2

Lucent Technologies Inc.

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

Ω impedance.

The laser module is equipped with

maintaining fiber (PMF). The fiber is PANDA type and is the

same fiber that is used on Lucent Technologies Microelec-

tronics Group’s lithium niobate modulators. It has a mode

field diameter of 10.5

µm, a cladding diameter of 123 µm—

128

µm, and a loose tube jacketed fiber 900 µm in diame-

ter. The pigtail is terminated with an

shows the orientation of polarization in the fiber.

Lucent’s optoelectronic components are being qualified to

rigorous internal standards that are consistent with

Telcor-

facturing operations are

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 Bell Communications

Research, 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.

Top view.

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

7

8

Case Ground

9

Case Ground

10

Case Ground

11

12

RF Laser Input Cathode (–)

13

14

Case Ground

1-771(C).a

CORE

STRESS ROD

PRINCIPAL POLARIZATION

AXIS

CLADDING

INNER COATING

(SILICON & ACRYLATE)

OUTER COATING

(ACRYLATE OR NYLON)

1-567

TEC

L1

160 nH

ISOLATOR

R1

20

Ω

PACKAGE

GROUNDS

–+

+

–

–

+–

+

76

5

4

3

2

1

8

9

10

11

12

13

TH

10 k

Ω

14