OPTICAL SUBCARRIER TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an optical subcarrier transmission system that separates a transmission signal and secondary intermodulation distortion without signal deterioration. SOLUTION: A reference laser diode 10 generates a reference optical signal with a carrier frequency fopt0, a laser diode 11 generates a 1st optical signal with a subcarrier frequency fopt1, and a laser diode 12 generates a 2nd optical signal with a subcarrier frequency fopt2. An optical modulator 111 modulates the 1st optical signal according to another data signal. An optical multiplexer 80 multiplexes a reference optical signal with the 1st and 2nd optical signals and transmits the multiplexed signal via an optical fiber cable 60 and provides an output to a photo diode 90 of a photoelectric conversion element via an optical fiber cable 60. The frequencies fopt0, fopt1, fopt2 are selected so that a difference frequency fopt0-fopt1 and a difference frequency fopt2-fopt0 are not in duplicate and a relation of fopt1