Tuning external cavity lasers within CWDM transmitters for temperature insensitivity and superchannel construction

摘要

A technique relates to a self-calibration routine for a laser with respect to a multiplexer. Electrical power is stepped up to a filter within the laser while monitoring transmission through multiplexer to store a current and maximum recorded transmission through multiplexer until minimum operating power is reached. If the current transmission through multiplexer at minimum operating power has fallen by more than predefined amount relative to maximum recorded transmission, the electrical power is stepped up to filter until the current transmission is restored to the predefined amount of the maximum recorded transmission, determining self-calibration for a blue edge of the multiplexer pass band. If current transmission through multiplexer at minimum operating power has not fallen by more than predefined amount relative to the maximum recorded transmission, electrical power is stepped up to filter until the current transmission falls to predefined amount of maximum recorded transmission, determining self-calibration for red edge.

主权项

1. A method for a semiconductor chip, the method comprising:
the semiconductor chip includes an intra-cavity optical bandpass filter which is coupled to a modulator which is coupled to a WDM multiplexer; executing, by a microcontroller, a self-calibration routine for calibrating to a wavelength division multiplexing (WDM) multiplexer of the semiconductor chip, wherein the self-calibration routine includes: driving the modulator to maximize transmission through the modulator; stepping up electrical power to the intra-cavity optical band-pass filter while monitoring transmission through the WDM multiplexer in order to store a maximum recorded transmission and a current transmission through the WDM multiplexer, wherein the WDM multiplexer has a WDM multiplexer pass band; when the current transmission through the WDM multiplexer has fallen by more than a predefined amount relative to the maximum recorded transmission, stepping up the electrical power to the intra-cavity optical band-pass filter until the current transmission is restored to the predefined amount of the maximum recorded transmission, thereby determining self-calibration parameters for a blue edge of the WDM multiplexer pass band; when the current transmission through the WDM multiplexer has not fallen by more than the predefined amount relative to the maximum recorded transmission, stepping up the electrical power to the intra-cavity optical band-pass filter until the current transmission falls to the predefined amount of the maximum recorded transmission, thereby determining the self-calibration parameters for a red edge of the WDM multiplexer pass band; and storing the self-calibration parameters in memory.