| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical transmission circuit in which variation of input power supply voltage or variation of the optical output caused by noise is reduced, and power consumption can be reduced. <P>SOLUTION: The optical transmission circuit 1 comprises an optical semiconductor element 10 integrating a laser diode 11 and an electroabsorption optical modulator 12 having a common cathode connected with an input power supply (input power supply voltage Vin), a modulation drive circuit 20 operating with the input power supply voltage Vin and supplying a modulation signal to the anode of the electroabsorption optical modulator 12, an LD drive circuit 30 supplying a bias current to the anode of the laser diode 11, a booster circuit 40 generating a step-up voltage Vout of the input power supply voltage Vin and supplying the step-up voltage Vout, as the power supply voltage, to the LD drive circuit 30, and a voltage control circuit 50 controlling the booster circuit 40 to change the step-up voltage Vout according to variation of the input power supply voltage Vin. <P>COPYRIGHT: (C)2012,JPO&INPIT |
