| 摘要 |
PROBLEM TO BE SOLVED: To select/receive the signal light (channel) of arbitrary wavelength in the photodetector of a reception-side in a wavelength multiplex optical trans mitting system. SOLUTION: The signal light beams (λ1 -λn ) of the respective channels are modulated with different frequencies f1 -fn as channel identification information, are multiplexed by a multiplexer 3 and are transmitted. On the reception-side, a branching filter 5 branches the beams and signals are supplied to the respective photodetectors 7-1 to 7-n through wavelength variable filters 6-1 to 6-n. At the time of receiving the channel of λ1 by the photodetector 7-1, the extraction filter of f1 is provided in the photodetector 7-1, and a control part 8-1 sweeps the wavelength selection characteristic of the filter 6-1. When f1 is detected, the wavelength selection characteristic of the filter 6-1 is maintained to λ1. |
