| 摘要 |
PURPOSE: To realize a phase non-sensitive and/or polarization non-sensitive optical heterodyne reception by shifting a transmission signal or a local oscillator signal between specified polarized states and obtaining an intermediate frequency signal by integration continuing heterodyne signal for the quarter of respective clock times. CONSTITUTION: The transmission signal S is supplied to a phase switch PhU and it is shifted between 0 deg. and 90 deg. at the start point A1 and a center point M of clock time T. The transmission signal which is phase and polarization- shifted is supplied to the optical directional coupler RK of an optical heterodyne receiver UE and it is overlapped with an optical local oscillator signal LS which is linearly polarized. An electric heterodyne signal US is generated after opto-electric conversion. The intermediate frequency signal ZF is filtered in an intermediate frequency filter ZFF integrating the supplied heterodyne signal US for the quarter of clock time T and it is demodulated in a demodulator DEM. Thus, the optical heterodyne reception of phase and/or polarization non- sensitivity can be realized. |
