CONTROL METHOD FOR SELECTIVE CHARACTERISTICS OF OPTICAL DEMULTIPLEXER

摘要

PURPOSE:To attain a stable selective characteristic by demultiplexing the output of a semiconductor laser device and controlling the value of a bias current so that the branched output is always maximum. CONSTITUTION:A signal demultiplexed from an optical waveguide is detected, and the value of the bias current is so controlled that the detection output is always maximum. That is, a current quantity controller 5 controls the bias current outputted from a driving current source 6 so that the output of a photodetector 4 is always maximum, and the driving current source 6 controls the bias current supplied to the semiconductor laser device so that it is smaller than the oscillation threshold. Thus, a stable selective characteristic is attained.