| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical analog transmission device which secures a wide dynamic range and can suppress optical beat noise at the time of SCM(sub- carrier multiplex)-multiplexing analog signals from a plurality of slave stations and transmitting them to a master station. SOLUTION: In slave stations 1a, 1b,-1n, optical signals obtained by directly modulating Fabry-Perot semiconductor laser elements 8a, 8b,-8n with an optical modulation degree larger than '1' by a frequency modulation signal modulated by an information signal being an analog signal are transmitted through an optical fiber 2 and are SCM-multiplexed with an optical signal from another slave station on a transmission line. In a master station, the optical signals which are SCM-multiplexed are collectively received by one photodetector 9. The signal of the desired slave station is extracted from the reception signal. A bias-tee 6 adds DC bias, a demodulation circuit 14 demodulates a frequency and an information signal is obtained. |
