| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a non-cooled optical semiconductor device in which a bias voltage of an electroabsorption optical modulator is accurately controlled so as to maintain an average intensity of an optical modulation signal constant with a simple configuration. <P>SOLUTION: A semiconductor laser 1 emits laser light. The light volume of laser light absorbed by the electroabsorption optical modulator 2 varies according to the voltage applied to the electroabsorption optical modulator 2. When the electroabsorption optical modulator 2 absorbs laser light, a light absorption current is generated. A monitoring photodiode 4 monitors back-face light of the semiconductor laser 1. An APC (Auto Power Control) circuit 5 feeds back the receiving current of the monitoring photodiode 4 to a bias current which is supplied to the semiconductor laser 1. A bias circuit 6 feeds back the average of the light absorption current of the electroabsorption optical modulator 2 to the bias voltage to be applied to the electroabsorption optical modulator 2. <P>COPYRIGHT: (C)2012,JPO&INPIT |
