SEMICONDUCTOR LASER OPTICAL OUTPUT CONTROL CIRCUIT AND OPTICAL DEVICE

摘要

A semiconductor laser optical output control circuitgv that precisely controls the optical output of a semiconductor laser. This circuit comprises a peak value detecting circuit 106-1 and bottom value detecting circuit 107-1 for detecting the output of a photodiode PD102, optical power setting voltage sources 105-11, 105-2 for imparting the set value of the optical output of the semiconductor laser LD101, a peak value detecting circuit 106-2 and bottom value detecting circuit 107-2 for detecting the output of a switching circuit 104 which changes the set value, error amplifiers 108-1, 108-2 for comparing the detection outputs of the bottom value detecting circuit 107-1 and bottom value detecting circuit 107-2, and a switching circuit 110 which synchronizes with the switching circuit 104 and changes the comparison results of error amplifiers 108-1, 108-2 to feed them to a current amplifier 111.