| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light receiving optical amplifier circuit capable of detecting the amount of the input light by maintaining high-speed response characteristics even at the time of large light amount input and preventing the saturation. <P>SOLUTION: The light receiving optical amplifier circuit 1 is constituted in such a manner that a first stage amplifier circuit 2 converts the current signal of a photodiode 11 into a voltage signal and a first rear stage amplifier circuit 3 amplifies the voltage signal to process a light receiving signal as a reproducing/writing signal and output it as an output voltage V1 from a reproducing/writing signal control output terminal 101. A second rear stage amplifier circuit 4 amplifies the voltage signal from the first stage amplifier circuit 2 to process the light receiving signal as an input light amount detecting signal and output it as an output voltage V2 from an input light amount detection output terminal 102. Thus, the input light amount of the photodiode 11 is detected separately from the processing of the reproducing/writing signal, and gains are independently set in the first rear stage amplifier circuit 3 and the second rear stage amplifier circuit 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
