Circuit, Optical Module, Methods and Optical Communication System for Dual Rate Power Point Compensation

摘要

A dual-rate power point compensating circuit, comprising a microprocessor and a transmitter optical subsystem assembly (TOSA), wherein the TOSA includes a laser connected to a laser driver, a monitor photodiode (MPD) connected to the laser driver, and a current divider connected to the microprocessor and the MPD. When a feedback current from the MPD exceeds the adjustable and/or operating range of the laser driver, the feedback current is reduced so that it is kept in the adjustable and/or operating range of the laser driver. The laser driver determines the optical output power of the laser from the value of the reduced feedback current. The circuit and method extend the adjustable and/or operating range of a laser driver and enable it to regulate a target optical output power of the laser with a broad testing range and high accuracy when the feedback current is relatively high.

主权项

1. An optical transmitter, comprising:
a laser driver; a transmitter optical subassembly (TOSA), comprising a laser connected to the laser driver, and a monitoring photodiode (MPD) receiving light from said laser and providing a feedback current to said laser driver, wherein said laser driver and said laser operate in a first mode and a second mode; a current divider connected to said MPD, configured to reduce said feedback current from said MPD when said laser operates in said first mode; a microprocessor configured to activate said current divider in the first mode and deactivate said current divider in the second mode; wherein said laser driver is configured to determine the output power of said laser from said feedback current reduced by said current divider in the first mode, and directly from said feedback current in the second mode.