Fujitsu Corporation

Takuma Shoji

Ichiro Nakajima

Takashi Honda

Satoru Saitoh

Masashige Kawarai

There is provided an optical transmission device including a light source configured to generate light used for coherent detection processing of reception light; a monitor configured to monitor a frequency offset between the reception light having a plurality of protection wavelengths and the light generated by the light source, based on a signal obtained by the coherent detection processing of the reception light having the plurality of protection wavelengths available for a work wavelength by the light generated by the light source; and a controller configured to select a protection wavelength to be switched to the work wavelength among the plurality of protection wavelengths, based on the frequency offset monitored by the monitor.

Optical transmission device and protection wavelength selection method

An optical transmission device includes: a spectral element configured to disperse an incident light beam in a first direction according to a wavelength of the incident light beam; a mirror array configured by a plurality of mirrors, each mirror having a reflective surface in which a reflection angle is adjustable and to which the incident light beam dispersed in the first direction is incident, the reflective surface being arranged on a plane formed by the first direction and a second direction orthogonal to the first direction; a plurality of ports arranged in the second direction; and a controller configured to adjust the reflection angle, so that a light beam reflected at the reflective surface is outputted to the port according to a region segmented in the second direction in the mirror array, the dispersed incident light beam that has a specified wavelength band being incident to the reflective surface.

Optical transmission device and optical transmission method

An optical transmission apparatus includes an amplifier, a first output port to select a wavelength from the wavelength-division-multiplexed signal light amplified and output signal light with the selected wavelength to an operation line, a second output port to output multiplexed light obtained by multiplexing any one of first spontaneous emission light and second spontaneous emission light to a preliminary line, the first and the second spontaneous emission light being parts of spontaneous emission light generated by the amplifier, the first spontaneous emission light being in a wavelength range that is not selected, and the second spontaneous emission light being in a wavelength range other than a range of the wavelength-division-multiplexed signal light, and a judger to judge a continuity state of the operation line by using the signal light output to the operation line and a continuity state of the preliminary line.

Optical transmission apparatus and continuity testing method

An optical transmission apparatus includes a network, a plurality of transponders, a monitor, a multiplexer, and demultiplexer. The plurality of transponders connected with the network, each of the plurality of transponders having a response transfer processing unit for communicating between the other transponders via the network, the plurality of transponders categorized a first transponder and a second transponder; The monitor connected with each of the transponder units, respectively, the monitor monitoring the plurality of transponders and sending a first request and a second request to the plurality of transponders. The first transponder responds an answer to the monitor via the network when the first transponder receives the first request. The second transponder responds an answer to the monitor instead of the first transponder via the network when the first transponder receives the second request.

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Yokohama, Japan

Takuma Shoji