SBH52414x

Description

Data Sheet

3

2002-05-28

Description

The Infineon module for bidirectional optical transmission has been designed for

different optical networks structures.

In the last few years the structure has changed from point to point planned for Broad

band ISDN to a point to multipoint passive optical network (PON) architecture for the

optical network in the subscriber loop.

A transceiver can be realized with discrete elements (Figure 3). Transmitter and

receiver with pigtails are connected with a fiber-coupler (2:1 or 2:2, wavelength

independent or WDM).

Figure 3

Realization with Discrete Elements

Infineon has realized this transceiver configuration in a compact module called a BIDI

®

(Figure 4).

This module is especially suitable for separating the opposing signals at the ends of a

link. It replaces a discrete solution with a transmitter, receiver and coupler.

The basic devices are a laser diode and a photodiode, each in a TO package, plus the

filter in the beam path. A lens in the TO laser concentrates the light and enables it to be

launched into the single-mode fiber of the module. In the same way the light from the

fiber is focused onto the small, light-sensitive area of the photodiode to produce a high

photo current. The mirror for coupling out the received signal is arranged in the beam so

that the transmitter and receiver are at right angles to each other. This means the

greatest possible degree of freedom in the layout of the electric circuit.

Coupler

2:1 or 2:2

3 dB wavelength independent

or wavelength division multiplexing

Transmitter

Receiver