Optical receiver

摘要

An optical receiver controls the amplitude of a light signal at a constant level so as to be constant for improvements in the quality of signal regeneration and reliability. A modulation part modulates the amplitude of the light signal. An opto-electric conversion part converts the output signal of the modulation part into an electric signal. A gain varying part amplifies the electric signal. A control part controls the gain of the gain varying part so that a variation width of the envelope line after signal amplification becomes close to a given value. A regeneration part compares the signal after amplification with a given threshold value for signal decision.