Abstract: The An opto-electro hybrid harness includes, at locations away from first and second connectors, a first relay segment having an EO conversion device, and a second relay segment having an OE conversion device. First and second electric cables lie between the first connector and the first relay segment and between the second connector and the second relay segment. An opto-electric hybrid cable segment lies between the first and second relay segments. An optical fiber is connected at one end to the E0 conversion device and at the other end to the OE conversion device. A first electronic wire of the first electric cable is connected at one end to the first connector and at the other end to the E0 conversion device. A second electronic wire of the second electric cable is connected at one end to the OE conversion device and at the other end to the second connector.

Abstract: An opto-electro hybrid harness includes, at locations away from first and second connectors, a first relay segment having an EO conversion device, and a second relay segment having an OE conversion device. First and second electric cables lie between the first connector and the first relay segment and between the second connector and the second relay segment. An opto-electric hybrid cable segment lies between the first and second relay segments. An optical fiber is connected at one end to the EO conversion device and at the other end to the OE conversion device. A first electronic wire of the first electric cable is connected at one end to the first connector and at the other end to the EO conversion device. A second electronic wire of the second electric cable is connected at one end to the OE conversion device and at the other end to the second connector.

Abstract: A method capable of stably drawing an optical fiber with a gas-seal system and an apparatus for implementing the method. The method produces an optical fiber 40b by drawing the optical fiber preform 30 by heating and softening the leading-end portion of it while feeding it into a drawing furnace 20. The drawing furnace 20 allows a gas 15 to blow against the optical fiber preform 30. The inside of the drawing furnace 20 is sealed with a seal ring 14U and a shutter 14L located at the top and bottom portions of it, respectively. While the gas 15 is fed, the inner diameter of the seal ring 14U is adjusted according to the diameter of the optical fiber preform 30. Consequently, even when the preform diameter varies, the clearance between the seal ring 14U and the optical fiber preform 30 can be maintained constant, thereby enabling a stable drawing operation.

Abstract: A process for producing a porous glass preform for optical fiber by depositing fine glass particles on an outer surface of a glass material while moving the glass material, including the steps of: preheating a portion of the glass material for not less than 5 minutes to clean the portion of the glass material in an apparatus for depositing fine glass particles; and depositing fine glass particles on the portion of the glass material cleaned by the preheating, in the apparatus for depositing fine glass particles.

Abstract: An optically active device comprising an optical fiber, a light source and an optical device is disclosed. The optical fiber comprises a core made of an optical functioning glass doped with Pr.sup.3+ as an active ion and transmits light at a first wavelength. The light source generates excitation light at a second wavelength shorter than the first wavelength. The optical device directs the excitation light from the light source into the optical fiber. Then, Pr.sup.3+ in the core of the optical fiber is stimulated to emit light at the second wavelength. As a result, an optical function such as optical amplification can be effected at the second wavelength.

Abstract: An optically active device comprising an optical fiber, a light source and a coupler is disclosed. The optical fiber has a core made of a silicate glass containing Rb and/or Cs oxide. The core is doped with Nd.sup.3+ as an active ion and transmits light at 1.3 .mu.m band. The light source generates excitation light at 0.8 .mu.m. The coupler directs the excitation light from the light source into the core of the optical fiber. A signal light or a spontaneous light at 1.3 .mu.m band which is transmitted in the core stimulates Nd.sup.3+ to emit light at 1.3 .mu.m band. As a result an optical function such as optical amplification can be effected at 1.3 .mu.m band.

Abstract: The present invention relates to an optical functioning glass containing Nd.sup.+3 as an active ion which amplifies an input light, and at least one other optical active ion different from Nd.sup.+3 which absorbs light at and near 1 .mu.m. The present invention also relates to an optical functioning glass containing Nd.sup.+3 as an active ion which amplifies the input light, and at least one other optical active ion different from Nd.sup.+3 functioning as a promoter. An efficiency of the stimulated emission of Nd.sup.3+ caused by signal light propagated through the optical functioning glass is enhanced and a gain of the light amplification at 1.3 .mu.m is increased.

Abstract: There is provided a method of producing a protective metal coated or covered superconducting ceramic wire by applying a finely pulverized protective metal-dispersed polymeric resin onto the surface of a glass wire in amorphous state of metal oxides capable of being converted into superconductive ceramic, heating the wire to remove the polymeric resin therefrom to obtain the wire having a metal powder coating thereon, and heat-treating the wire to become superconductive. The coating is easily conducted without damaging the excellent productivity of the so-called melt-quenching and preform wire-drawing process for producing a superconducting ceramic wire.

Abstract: There is provided a drawing process for producing an optical fiber which comprises drawing the optical fiber from a preform therefor under tension to form the optical fiber while heating and melting the preform, wherein an outer diameter of the optical fiber on which no coating has been provided is measured at a position at which shrinkage of the outer diameter of the optical fiber, while stretched, is not larger than 0.5% and drawing conditions are controlled based on the deviation of the measured diameter from a preselected outer diameter.

Abstract: A process for producing an image fiber comprising drawing an image fiber preform consisting of a bundle of a plurality of optical fibers each of which is drawn from an optical fiber preform and consists of a core and a cladding, in which at least one of the optical fiber preform, the optical fiber, the image fiber preform and the image fiber is hydrogenated at a temperature higher than a room temperature, the image fiber produced having improved attenuation which is less increased when it is irradiated, particularly with gamma-ray.