Abstract: A wavelength tunable light source includes a wavelength tunable laser device and a control device. The wavelength tunable laser device includes: M laser diodes configured to generate laser oscillation to output beams; a multiplexer/demultiplexer configured to multiplex the beams output from the M laser diodes to bifurcate the beams for output; a first semiconductor optical amplifier configured to amplify one output beam of the bifurcated beams to output a first emitted beam; and a second semiconductor optical amplifier configured to amplify another output beam of the bifurcated beams to output a second emitted beam. The control device is configured to perform wavelength switching control on wavelengths of the first emitted beam and the second emitted beam by switching an electric power input to the second semiconductor optical amplifier.

Abstract: An optical transmission apparatus (100) includes an optical transmitter (200) including an optical modulator (220) and an observation optical modulator (230) that attenuate optical power of input continuous wave light by an electro-absorption effect and output the continuous wave light. The optical modulator (220) performs pulse amplitude modulation on the continuous wave light and outputs the optical signal.

Abstract: An optical transmission apparatus includes an optical transmitter including an optical modulator and an observation optical modulator that attenuate optical power of input continuous wave light by an electro-absorption effect and output the light. The optical modulator performs pulse amplitude modulation on the continuous wave light and outputs the optical signal. The apparatus also includes: a bias voltage generation unit that generates a direct-current bias voltage and outputs the direct-current bias voltage to the optical modulator and the observation optical modulator; a modulation signal generation unit that generates an electrical signal for pulse amplitude modulation and outputs the electrical signal to the optical modulator; and a bias voltage control unit that instructs the bias voltage generation unit to adjust the direct-current bias voltage on the basis of an absorption amount of optical power in the optical modulator and an absorption amount of optical power in the observation optical modulator.

Abstract: An optical relay of an optical transmission system includes an optical transmission network formed by a plurality of the optical relays and a network management apparatus that manages the optical transmission network. The optical relays each include an optical transmitter that can generate an optical signal of a specific wavelength, a transmission wavelength selective switch that can switch a path on a wavelength basis, and a transmission compensation control unit that controls the optical transmitter. When the transmission compensation control unit receives, from the network management apparatus, information on the band limitation occurrence frequency that is the number of occurrences of band limitation when the optical signal generated by the optical transmitter passes through another one of the optical relays, the transmission compensation control unit adjusts a frequency of the optical signal by changing a setting of the optical transmitter on the basis of the information received.

Abstract: A wavelength tunable light source includes a wavelength tunable laser device and a control device. The wavelength tunable laser device includes: M laser diodes configured to generate laser oscillation to output beams; a multiplexer/demultiplexer configured to multiplex the beams output from the M laser diodes to bifurcate the beams for output; a first semiconductor optical amplifier configured to amplify one output beam of the bifurcated beams to output a first emitted beam; and a second semiconductor optical amplifier configured to amplify another output beam of the bifurcated beams to output a second emitted beam. The control device is configured to perform wavelength switching control on wavelengths of the first emitted beam and the second emitted beam by switching an electric power input to the second semiconductor optical amplifier.

Abstract: An optical transmission device includes a data duplicating unit that duplicates signals of each of the lanes subjected to symbol mapping and sets the number of the lanes to the number of lanes of a first number; a waveform converting unit that waveform-converts a signal that can take a value of a type of a second number into a signal that can take a value of a type of a third number larger than the second number; a polarity inverting unit that inverts polarity; a lane replacing unit that performs replacement of lanes in two or more lanes; and an optical-signal generating unit that converts electric signals of the signals of each of the lanes input from the lane replacing unit into optical signals and combines and outputs the optical signals of the lanes.