| 摘要 |
PURPOSE:To allow the constant output of a local oscillator to follow up the frequency and phase fluctuations of light input signal at all times by constituting an optical PSK homodyne detecting and receiving device with the local oscillator synchronized to the frequency and phase of the entered light input signal, etc. CONSTITUTION:The signal PSK modulated from the input signal obtained at an input terminal 1 is separated and is divided to signals 3, 4, by a half mirror 2. The signal light 4 passes through a half mirror 5 and enters a square detector 6, whilist the light 19 out from a VCO7 reflects on the mirror 5, is combined with the signal light 4, and is simultaneously entered to the square detector 6. If the light 19 coincides with the carrier of the input signal of the input terminal 1, the output base band signal 17 can be directly taken out from the square detector 6. Namely, this is the constitution of obtaining the locally transmitted light by operating the optical VCO7 by the use of the reverse modulation type homodyne detection system in order to make the sufficient optical reference phase carrier. |
