Abstract: An optical fiber board has a substrate, optical fiber arranged as wiring on the substrate, and extension portions in each of which some optical fibers are led out from the substrate to be adjacent to each other in a row. The adjacent optical fibers at a base portion of the extension portion are not fixed to one another. The adjacent optical fibers at a forward end portion of the extension portion are fixed to one another integrally. The base portion has a predetermined length from an edge portion of the substrate.

Abstract: An optical fiber board has a substrate 2, optical fibers arranged as wiring on the substrate 2, and extension portions 10 in which the optical fibers are led out from the substrate. The optical fibers in the extension portions 10 are covered with protective tubes 5 for protecting the optical fibers. One end portion 51 of each of the protective tubes 5 is attached to corresponding ones of notch portions 4 provided in an end edge portion of the substrate 2 from which the optical fibers are extended out.

Abstract: A flexible tube having a construction in which a coil of metal is coated with a film of resin. The flexible tube is manufactured by that resin is vapor-deposited on a peripheral face of a thermocontraction tube. a metal wire is wound on the tube as to be coiled, resin is vapor-deposited on the coil, and the thermocontraction tube is contracted by heating and drawn out.

Abstract: A rotating shaft seal provided with a seal element, arranged between a housing and a rotation shaft, which contacts the rotation shaft, and a seal member made of rubber having a lip end portion, disposed on a fluid storing chamber side to the seal element, which contacts the rotation shaft, comprising a supporting metal for supporting a rear face of the seal member of rubber.

Abstract: A rotating shaft seal provided with a seal element, arranged between a housing and a rotation shaft, which contacts the rotation shaft, and a seal member made of rubber having a lip end portion, disposed on a fluid storing chamber side to the seal element, which contacts the rotation shaft, comprising a supporting metal for supporting a rear face of the seal member of rubber.

Abstract: A connector structure provided with a coaxial connector having an inner contact and an outer contact respectively connected to an inner conductor and an outer conductor of a coaxial cable having the inner conductor and the outer conductor respectively insulated, in which the inner contact has a tapping screw portion screwed into an inner peripheral face of the hollow inner conductor as to do self screw cutting, and the tapping screw portion has a guiding portion, formed parallel to an axis and having an outer diameter approximately same as an inner diameter of the inner conductor, on its forth end.

Abstract: An optical fiber coupler for optical fiber amplifier use in the field of optical communications is provided. The optical fiber coupler comprises: a rare earth-doped fiber as an optical amplifying element; a quasi rare earth-doped fiber for entrance of input signal light; a fused-stretch fiber portion as a multiplexing element which connects a part of the rare earth-doped fiber and a parts the quasi rare earth-doped fiber, wherein the fused-stretch fiber portion formed by stretched a fused mixture of parts of the rare earth-doped fiber and the quasi rare earth-doped fiber; and a single mode fiber which is jointed at a fused joint portion to another shortened rare earth-doped fiber connected to the fused-stretch fiber portion on a side connected by the quasi rare earth-doped fiber. The quasi rare earth-doped fiber has substantially equal propagation constant to the rare earth-doped fiber without substantially containing rare earth elements.

Abstract: A rotating shaft seal provided with a seal element, arranged between a housing and a rotation shaft, which contacts the rotation shaft, and a seal member made of rubber having a lip end portion, disposed on a fluid storing chamber side to the seal element, which contacts the rotation shaft, comprising a supporting metal for supporting a rear face of the seal member of rubber.

Abstract: A silica optical fiber is provided, which contains a pure-silica core and a cladding layer formed on the pure-silica core, wherein the pure-silica core contains a C element and has a content of elements belonging to the third period-the seventh period of the periodic table, except Si element that constitutes the quartz structure, of not more than 100 ppm. The present invention can provide a silica optical fiber superior in the resistance to high energy electromagnetic waves such as UV light and &ggr;-rays.

Abstract: In order to achieve constantly stable, high seal performance without requiring high machining accuracy, and in order to provide a reusable jacket seal, the present invention discloses a jacket seal, wherein a projection is formed at a position of a metal jacket in opposite relationship with a seal surface of a member being sealed, a flat portion is formed in an elastic member within the metal jacket so as to be brought into surface-to-surface contact with a flange portion interior surface, and the vertex portion of the projection is formed flat.

Abstract: A connector structure provided with a coaxial connector having an inner contact and an outer contact respectively connected to an inner conductor and an outer conductor of a coaxial cable having the inner conductor and the outer conductor respectively insulated, in which the inner contact has a tapping screw portion screwed into an inner peripheral face of the hollow inner conductor as to do self screw cutting, and the tapping screw portion has a guiding portion, formed parallel to an axis and having an outer diameter approximately same as an inner diameter of the inner conductor, on its forth end.

Abstract: An insulating material for coaxial cables, made at least in part with a polyolefin resin capable of heat-melt extrusion and a fluororesin powder as a nucleator, which material being capable of foam extrusion in the presence of a foaming agent; a coaxial cable made at least in part with a foam insulating layer prepared from the insulating material; and a method for producing a coaxial cable, by extruding, on a conductor, the insulating material to form a foam insulating layer. The insulating material for coaxial cables of the present invention containing a fluororesin powder such as PTFE as a nucleator provides a foamed article having fine and uniform cells, and a high expansion ratio. Such foamed article is superior in electric properties, and the coaxial cable having such insulating layer is superior in attenuation property. The material of the invention can obviate drying of the insulating layer, which contributes to an improved production efficiency of the coaxial cable and reduced production cost.

Abstract: A connector structure provided with a coaxial connector having an inner contact and an outer contact respectively connected to an inner conductor and an outer conductor of a coaxial cable having the inner conductor and the outer conductor respectively insulated, in which the inner contact has a tapping screw portion screwed into an inner peripheral face of the hollow inner conductor as to do self screw cutting, and the tapping screw portion has a guiding portion, formed parallel to an axis and having an outer diameter approximately same as an inner diameter of the inner conductor, on its forth end.

Abstract: In an optical amplifier apparatus for amplifying an incident signal light having wavelengths of 1.06 &mgr;m band, a first optical isolator makes an incident signal light pass therethrough in one direction from an input end to an output end. An optical fiber includes a core mainly composed of silica glass and doped with a predetermined rare-earth element and the other elements, and a cladding of silica glass, and transfers in a single mode the signal light output from the first optical isolator. An optical multiplexer multiplexes an excitation light having an excitation wavelength of 0.8 &mgr;m band with the signal light transferred by the optical fiber, by outputting the excitation light to the optical fiber, and further transfers and outputs the signal light having wavelengths of 1.06 &mgr;m band amplified by induced emission in the optical fiber due to the rare-earth element excited by the excitation light.

Abstract: A shaft seal provided with a front seal member, disposed on a fluid storing chamber side and having a lip end portion of rubber which slides on a rotation shaft in rotation state. And the shaft seal is provided with a rear seal member disposed on a low pressure side and having a lip end portion of rubber which contacts the rotation shaft in static state.

Abstract: A ring seal contains a core made from an elastic organic polymer and a metal jacket having a U-shaped sectional shape, which jacket surrounds the core to prevent transfer of a substance generated from the core into the sealed space. The seal of the present invention does not release a foreign material into the sealed space, nor does it require a great force for clamping. Accordingly, it is useful as a vacuum seal that achieves miniaturization and reduced weight of a vacuum apparatus. In particular, by making the sectional shape of the metal jacket a U shape, the core can be easily detached and attached for fitting after forming the jacket, and the inside of the jacket can be washed easily.

Abstract: A method of preventing a high-frequency noise generated in an electronic device, remaining in a grounding cable as a standing wave and transmitted to electric devices, is disclosed, which method including disposing, directly or via an insulating layer, a non-metallic conductive material having a slight electric resistance, on a conductor of the above-mentioned grounding cable, making the electric resistance of the non-metallic conductive material consume the high-frequency noise flowing on the conductor surface of the grounding cable by virtue of a skin effect, whereby resonance of the high-frequency noise is reduced. Resonance of the high-frequency noise generated from various electronic devices in an office building and the like can be easily reduced. Consequently, various disadvantages due to high-frequency noise can be avoided.

Abstract: A GaN group crystal base member comprising a base substrate, a mask layer partially covering the surface of said base substrate to give a masked region, and a GaN group crystal layer grown thereon to cover the mask layer, which is partially in direct contact with the non-masked region of the base substrate, use thereof for a semiconductor element, manufacturing methods thereof and a method for controlling a dislocation line. The manufacturing method of the present invention is capable of making a part in the GaN group crystal layer, which is above a masked region or non-masked region, have a low dislocation density.

Abstract: A medical tube made of an organic polymer having a mechanical loss tangent of at least 0.5 at body temperature and a modulus of transverse elasticity of 1-1000 MPa at body temperature. The medical tube of the present invention can be easily inserted into the body, and gives less pain and less feeling of physical disorder during indwelling in the body or removal from the body.

Abstract: The object of the present invention is to provide an optical device which has obliterated, by the use of a nonlinear optical crystal, the need for a complicated adjustment operation of positions as seen in an optical device used for obtaining an output light having a frequency different from an input light. To be specific, Q switching electrodes 12A, 12B, phase adjustment electrodes 9A, 9B and periodic domain inversion part 15 are disposed in desired parts of path 2 in an optical crystal 1 having nonlinear optical character, electro-optical character and laser activity. By the action of an input light P0 supplied from an input side 3, oscillation light P1 is oscillated, harmonic is generated by nonlinear optical character and periodic domain inversion part 15, or output light P2 having a frequency different from that of input light P0 is emitted from output side 4 by optical parametric oscillation.