Patent ID: 7639954

Claim:
A modulation driver for delivering an output modulation current for driving an optical source of an optical transmitter, the output modulation current of said driver having first and second discrete linear modulation current regions, the first discrete linear modulation current region having a first temperature gradient and the second discrete linear modulation current region having a second temperature gradient, said second temperature gradient being larger than said first temperature gradient, said modulation driver comprising: a first modulation current source which is associated with the first temperature gradient and a second modulation current source which is associated with the second temperature gradient, the output modulation current of said modulation driver being delivered by said first modulation current source in a first temperature range and modulation current being delivered by said second current source in a second temperature range, said first and said second temperature ranges together forming a continuous temperature range, and wherein temperatures of said second temperature range are higher than temperatures of said first temperature range.