Patent ID: 8879915

Claim:
An optical add device comprising: a plurality of optical switching devices including: a plurality of wavelength selective switches that respectively have a first port being an output port and a plurality of second ports being input ports, an optical coupler that has a plurality of third ports on an input-side, respectively optically coupled with the first ports of the wavelength selective switches to couple optical signals output from output ports of the wavelength selective switches, a wavelength monitor that monitors each wavelength included among optical signals, a detector that detects, based on monitor results obtained by the wavelength monitor, optical signals which include a same wavelength, and a controller that causes any one of the wavelength selective switches which output one of the detected optical signals to terminate output of the optical signal when an optical signal which includes the same wavelength is detected, the plurality of the optical switching devices, respectively transmitting to degrees of a network, an optical signal coupled by the optical coupler; a plurality of transmitters that respectively output an optical signal; and optical paths that input to the input ports of the optical switching devices, the optical signals output by the transmitters and including: a plurality of cross connects that each have a plurality of input ports to which the optical signals output by the transmitters are input, and a plurality of output ports, a plurality of first switches that each have an input port that is optically coupled to an output port of one of the cross connects, and a plurality of output ports, a plurality of second switches that each have input ports that are optically coupled to the output ports of the first switches, and an output port, and a plurality of multiplexers that multiplex optical signals output from the output ports of the second switches and input the multiplexed optical signals to the input ports of the optical switching devices.