Abstract: An optical switch includes at least one input optical semi-conductor waveguide. Two output optical semiconductor waveguides are connected at a branch point to the input optical waveguide, and diverge from the branch point with a preset angle .theta. (degree) between them. A refractive index controlling portion is located on at least one of the output optical waveguides and away from the branch point. The refractive index controlling portion effects a light mode cut-off by electromagnetically causing a reduction of the refractive index of the associated output optical waveguide.

Abstract: There is provided an optical functional device having a coupling portion in which two optical waveguides formed of semiconductor material are evanescent-coupled to each other and arranged in parallel and comprising voltage application electrodes electrically connected to each other and disposed on an upstream side portion of one of the two optical waveguides and a downstream side portion of the other optical waveguide and current injection electrodes electrically connected to each other, disposed on an downstream side portion of the former one of the two optical waveguides and an upstream side portion of the other optical waveguide and electrically isolated from the voltage application electrodes; wherein N-stage (N is an integer larger than 2) electrodes of reversal .DELTA..beta.

Abstract: An optical switch includes at least one input optical semi-conductor waveguide. Two output optical semiconductor waveguides are connected at a branch point to the input optical waveguide, and diverge from the branch point with a preset angle .theta. (degree) between them. A refractive index controlling portion is located on at least one of the output optical waveguides and away from the branch point. The refractive index controlling portion effects a light mode cut-off by electromagnetically causing a reduction of the refractive index of the associated output optical waveguide.

Abstract: An optical component and a manufacturing method therefor are provided, in which an optical member is arranged across a spot-size enlarged portion of an optical fiber. The spot-size enlarged portion is formed either by heating and drawing an optical fiber to reduce its diameter or by diffusing core dopant of an optical fiber outwardly while heating the same. The optical component functions as an optical filter, an optical attenuator, a polarizer, a wavelength division multiplexer/demultiplexer or the like, depending on selection of the optical member.

Abstract: A method for switching an optical connector having paired optical connectors, having pins engaged with engaging holes of the optical connectors, which involves a connector disposing step of disposing the switching optical connector parallel to the separating optical connector, a pin forward moving step of moving the pins engaged with both the reconnecting and separating optical connectors each other to the reconnecting optical connector side, then a connecting switching step of relatively moving the reconnecting optical connector, the separating optical connector and the switching optical connector and the front end faces thereof, and finally pin backward moving step of moving the pins of the reconnecting optical connector side to the switching optical connector side.

Abstract: Opposed ones of optical fibers respectively secured in a plurality of guide grooves formed in first and second blocks, are jointed to each other through an optical film formed on at least one of their opposed inclined end faces in such a way that their optical axes are aligned with each other. Further, each of optical fibers similarly disposed on a third block is formed at its one end face with a total reflection film and is arranged in parallel to the optical fibers of the first and second blocks in such a way that an optical signal incident to the respective fibers of the first block is propagated through the splitting films and total reflection films along optical axes of the associated optical fibers of the third block.

Abstract: An optical switch system used in a monitoring system for monitoring a large-scale optical transmission including a multiplicity of optical fibers, or like systems for switching optical transmission paths. The optical switch system comprises first and second optical switches. The first optical switch serves to optically connect one end face of a single first optical fiber selectively to one end face of any one of n second optical fibers. The second optical switch serves to optically connect end faces of n third optical fibers collectively and substantially synchronously to end faces of fourth optical fibers of a desired bundle selected from a plurality of optical fiber bundles each composed of substantially n optical fibers, the third optical fibers being optically connected at other end faces to other end faces of the second optical fibers.

Abstract: A polling communication method which asks whether or not there is a request with data from a range of answer requesting terminals. A request is determined by a binary looking-up to terminals by a center. The center and the terminals are connected through a common signal transmission line, replying to the center that there is a request with a self-address to the requesting terminal. There is a further reducing of the range of answer requesting terminals by sequentially determining, according to a binary looking-up to specify one of the requesting terminals when a collision of the requests occurs between the terminals at the replying time. The center then asks the content of the request to the specified terminal. Thus, this method can process requests at a high speed, not only when the rate of requests of terminals is low but also when the rate of requests of terminals is high and often collide.