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 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: 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 closure for a cable connector covered at the ends of the cables connected to each other in a sleeve through end face plates for closing both ends of the sleeve. Grasping fittings are mounted at the ends of the cable contained in the sleeve which has axial restricting means and/or rotational restricting means provided in the sleeve for preventing the grasping fittings from moving axially and/or rotationally. Thus, the closure can provide mechanical strength sufficient for enduring loads such as tension, compression and twist transmitted through the cables.