| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical receiver which can eliminate noise components from a returned light signal overlaid with noise, when amplifying the returned light signal. SOLUTION: The return light 25, overlaid with noise, is converted into a current signal by means of a photodiode 1 and then is converted into a voltage signal 9 by means of a current/voltage (I-V) conversion section 7. The voltage signal 9 is inputted into an inversing input terminal 4 of an operational amplifier 2 and at the same, is inputted also to a filter 8. The filter 8 extracts low-frequency noise components from the voltage signal and then inputs the components into a non-inverting input terminal 6. The operational amplifier 6 eliminates only the low-frequency in-phase noise components from the inputted signal and the conducts amplification operation. |
