Patent ID: 7061950
Filing Date: 2006-06-13
Classification: G02F,H01S

Abstract:
1. A drive circuit for driving a semiconductor module including a semiconductor laser generating carrier light according to a drive current and an electro-absorption type optical modulator outputting an optical signal of which intensity is modulated by absorbing the carrier light output from said semiconductor laser according to a drive voltage, said drive circuit comprising: a laser drive unit supplying the drive current to said semiconductor laser; an optical modulator drive unit applying the drive voltage in which a modulated electric signal is superimposed on a bias voltage, to said electro-absorption type optical modulator; a temperature detection unit detecting the ambient temperature of said semiconductor laser and said electro-absorption type optical modulator; and a drive control unit controlling the drive current supplied by said laser drive unit and the drive voltage applied by said optical modulator drive unit, based on the temperature detected by said temperature detection unit, so that average power, an extinction ratio and an optical cross point of the carrier light output from said semiconductor laser are constant.