CONTROL CIRCUIT FOR LIGHT EMTTING SEMICONDUCTOR DEVICE

摘要

A digital servo control circuit controls light output from injection laser 12 providing an input to a communications optical fibre 16. A photodiode 10 senses the light output and operates analogue to digital converter (A/D), control logic 28 and D/A converter 30 to control the laser 12. A digital system 32 provides control information and receives status information. It also supplied a modulating control signal 38 to modulate the laser output about the servo established level.