| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical amplifier circuit which combines resistance to noise with high speed responsiveness. SOLUTION: The optical amplifier circuit includes: an amplifier 9 wherein a feedback resistor 8 is connected between an input and an output of an inverting amplifier 7; a bias setting circuit 16 whose constitution is the same as that of the amplifier 9; a photo diode 10 the anode electrode of which is connected to an input terminal 5 of the amplifier 9 and the cathode electrode of which is connected to an input terminal 17 of the bias setting circuit 16; and a capacitor 19 for interconnecting an output terminal 18 of the bias setting circuit 16 and the input terminal 5 of the amplifier 9, a current Ic flows through the capacitor 19 only at rise and fall of a waveform of a photo current Ipd, the current Ic is superimposed on the photo current Ipd, the resulting current is converted into a voltage by the feedback resistor 8, and causing an overshoot / undershoot at an output terminal of the amplifier 9 can attain a fast response. COPYRIGHT: (C)2005,JPO&NCIPI
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