Suppression of laser frequency drifts caused by thermal transients in optical WDM packet switching systems

Frequency drifts caused by laser thermal transients have been identified as a major impairment in packet switching networks using multisection tunable lasers. They are induced by the heating changes caused by current steps used to switch the carrier frequency. A method to suppress this frequency drift in a FSK-WDM direct detection system through the use of a passive equalisation circuit is presented.