Laser diode driving method and circuit which provides an automatic power control capable of shortening the start-up period

摘要

A technique for driving a laser diode on the basis of automatic power control (APC) is disclosed. The technique uses, for the bottom level feedback control, a constant reference voltage instead of a variable intermediate signal generated in the peak level feed back control. The constant reference voltage may be either a reference voltage for the peak level control or a separately generated voltage. A technique for setting the extinction ratio to 1/n is also disclosed.