| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a delay interferometer for stably and exactly demodulating an optical signal subjected to DQPSK modulation or DPSK modulation and a demodulator having the same. <P>SOLUTION: The delay interferometer has: a half mirror which branches the optical signal to first branched light and second branched light, emits the first branched light to a first optical path and emits the second branched light to a second optical path; a first reflector which is disposed on the first optical path and reflects the first branched light on the half mirror; a second reflector which is disposed on the second optical path and reflects the second branched light on the half mirror and a phase compensator which is arranged at least either of between the half mirror and the first reflector and between the half mirror and the second reflector and composed of a thermooptic effect medium having refractive index temperature dependency, wherein the half mirror multiplexes the first branched light made incident from the first reflector and the second branched light made incident from the second reflector, branches the multiplexed optical signal (multiplex optical signal) into two and emits them. <P>COPYRIGHT: (C)2008,JPO&INPIT |
