Method and system for controlling laser modulation

摘要

A system comprises drive circuitry 506 configured to apply in a start-up phase a first drive current and then a second different drive current to a laser diode 501, said first drive current and second drive current being such that said laser diode is configured to provide a first optical output and a second optical output respectively, an optical sensor 502 configured to provide a first sensor output corresponding to the first optical output of said laser diode and a second sensor output corresponding to said second optical output; and a controller 520 configured to use said first drive current, said second drive current, said first sensor output and said second sensor output to provide control values for said drive circuitry to control a modulation depth of said laser diode. The first and second drive currents may be single bursts. The optical sensor may be a photodiode.