Control circuit for constantly setting optical output of semiconductor laser

Abstract

A modulating electric current and a bias electric current supplied to a semiconductor laser can be respectively changed correspondingly with ambient temperature even in a burst mode, and the level of an optical output is constantly set at all times irrespective of the ambient temperature. An optical output control circuit has a semiconductor laser for supplying a modulating electric current and a bias electric current thereto, a modulating electric current supplying device for supplying the modulating electric current on the basis of an inputted modulating signal, and a bias electric current supplying device for supplying the bias electric current. A first temperature correcting device for increasing the modulating electric current with a rise in ambient temperature is arranged in the modulating electric current supplying device, and a second temperature correcting circuit for increasing the bias electric current with the rise in ambient temperature is arranged in the bias electric current supplying device.

Dependencies are inferred from the claim text.