Abstract: A package for an optical fiber includes: a base portion; a plurality of protruding portions that protrude from a flat surface of the base portion, are arranged along an outer periphery of the base portion, and are configured so that an optical fiber including a connector mounted to at least one end thereof is wound along a part of an outer periphery of each of the protruding portions; a mounting portion to which the connector of the optical fiber is to be mounted; and a plurality of fall-off preventing portions that are formed integrally with the base portion and capable of restricting a position of the optical fiber to be wound over the plurality of protruding portions.

Abstract: A silicon carbide semiconductor device has a silicon carbide semiconductor substrate of a first conductivity type, a first semiconductor layer of the first conductivity type and having a doping concentration lower than a doping concentration of the silicon carbide semiconductor substrate, a second semiconductor layer of a second conductivity type, first semiconductor regions of the first conductivity type, trenches, first base regions, second base regions of the second conductivity type, and a co-doped region doped with aluminum and nitrogen. The co-doped region is provided in the first semiconductor layer, including regions between the first base regions and the second base regions and a layer that is closer to the silicon carbide semiconductor substrate than are the first base regions and the second base regions. The co-doped region has a carrier lifetime of not more than 0.01 ?s.

Abstract: A package for an optical fiber includes: a base portion; a plurality of protruding portions that protrude from a flat surface of the base portion, are arranged along an outer periphery of the base portion, and are configured so that an optical fiber including a connector mounted to at least one end thereof is wound along a part of an outer periphery of each of the protruding portions; a mounting portion to which the connector of the optical fiber is to be mounted; and a plurality of fall-off preventing portions that are formed integrally with the base portion and capable of restricting a position of the optical fiber to be wound over the plurality of protruding portions.

Abstract: There is provided a transmission apparatus including: generators to generate optical signals having wavelengths included in a predetermined band, the wavelengths being variable; a transmitter to multiplex the optical signals and transmit the optical signals to another transmission apparatus; a memory; and a processor coupled to the memory and the processor to: monitor reception quality of an optical signal for monitoring received by the another transmission apparatus while changing a wavelength of the optical signal for monitoring which is generated by the generators, determine a first wavelength of a first optical signal having a longest wavelength and a second wavelength of a second optical signal having a shortest wavelength, based on the reception quality monitored, determine a wavelength of an optical signal except for the first and second optical signals, based on the first second wavelengths, and control the wavelength generated by the generators, based on the wavelength determined.

Abstract: An optical transmitter includes an optical isolator that includes a Faraday rotator transmitting light output from a light source, and has a first state in which the light is transmitted through the optical isolator when a first magnetic field is applied to the Faraday rotator, and a second state in which the amount of the light transmitted through the optical isolator is less than that in the first state when a second magnetic field different from the first magnetic field is applied to the Faraday rotator; a junction to which an optical transmission medium into which the light output from the optical isolator is input is connected; a magnetic-field generator that selectively applies the first magnetic field or the second magnetic field to the Faraday rotator; and a switching unit that switches the magnetic-field generator to the second state when the optical transmission medium is not connected to the junction.