| 摘要 |
PURPOSE:To extend a band width, to simplify the configuration and to improve the performance by propagating a data signal forward/backward through an optical fiber link and detecting the signal with a proper filter. CONSTITUTION:An electric synthesis signal detected and demodulated by a photoelectric detector 2 in an optical receiver R is given to a band pass filter 5 whose pass band is set in matching with a frequency of a reference carrier, in which a data signal is reflected and only the reference carrier signal is filtered. The carrier signal passes through a microwave circulator 8 and amplified. The amplified reference carrier signal again passes through the microwave circulator 8 and injected again to the photoelectric detector 2. The photodetector 2 acts like a frequency converter by a nonlinear reply of the photodetector at a high power level and the detected data signal is up-converted in the photodetector by the carrier signal. The data signal passes through a band pass filter 4, from which the signal is propagated to an output port 10. |
