OPTICAL RECEPTION DEVICE USING DQPSK DEMODULATION METHOD, AND DQPS DEMODULATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical reception device using a DQPSK demodulation method suitable for the reduction in size and cost of the device, and to provide the DQPSK demodulation method.;SOLUTION: A signal which has been extracted conventionally by using two delay interferometers can be extracted by one delay interferometer 130 by periodically changing a voltage value of an electric signal Vc(t) applied to one arm 130b of the delay interferometer 130 to periodically change a phase of light to π/4 and -π/4. The value of the voltage applied to one arm 130b is switched for intervals of τ/2 being a half of a symbol interval τ, whereby signal components which have been extracted conventionally by two delay interferometers alternately appear in an output of the delay interferometer 130 for intervals of τ/2.;COPYRIGHT: (C)2008,JPO&INPIT