OPTICAL RECEIVING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an optical receiving apparatus which allows relaxation of permissible specifications of a post stage band-pass filter in a light receiving circuit, and in some cases does not require the band-pass filter. SOLUTION: The light receiving circuit consists of a photodetector 1 which receives a frequency-multiplexed optical signal and converts the signal to a current signal, and a voltage-to-current converter pre-amplifier 2. A resistor 6 is connected to a power route of the photodetector. A serial connection circuit in which a second capacitor 5 for DC blocking is connected in serial is connected in parallel with the photodetector to a parallel resonance circuit consisting of an inductor 3 and a first capacitor 4. A resistance value of the resistor, an inductance of the inductor and a capacitance of the first capacitor are selected so that the output of the voltage-to-current converter pre-amplifier has a desired band-pass characteristic.