Patent ID: 7411725
Filing Date: 2008-08-12
Classification: G02B,H04B

Abstract:
1. A demodulator for demodulating an optical signal on which DPSK (Differential Phase Shift Keying) is applied, the demodulator comprising: a Michelson interferometer that includes: a half-mirror for splitting the optical signal into a first split light and a second split light, emitting the first split light to a first optical path, and emitting the second split light to a second optical path; a first reflector for reflecting the first split light to the half-mirror, the first reflector being disposed on the first optical path; and a second reflector for reflecting the second split light to the half-mirror, the second reflector being disposed on the second optical path, wherein the half-mirror recombines the first split light incident from the first reflector and the second split light incident from the second reflector, and emits a recombined optical signal while splitting the recombined optical signal in two branches; and two light receiving elements for receiving the recombined optical signals being emitted in two branches from the Michelson interferometer, wherein the balanced optical detector generates a demodulated signal based on the recombined optical signals,