Wavelength-multiplexed optical network system.

摘要

A wavelength separator in a wavelength-multiplexed optical network system uses a wavelength demultiplexer (2) having optical elements having wavelength selectivity arranged in tandem to directly demultiplex light signals by wavelength without distributing all input light signals. When a node device (A-E, M) is down, a power supply fails or a control signal is not issued, the received light signals are not demultiplexed but propagated through an optical wave-guide (2-1).