Sumitomo Electric Industries, Limited

Nippon Telegraph and Telephone Corporation

Takashi Kohgo

Masashi Onishi

Minoru Watanabe

Gotaro Tanaka

Yoshiki Chigusa

Tetsuya Ohsugi

Izumi Sankawa

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.

Optical fibre, waveguide, and optical active device

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.

Method of producing superconducting ceramic wire having protective metal

A superconducting ceramic wire is produced by melting a superconducting ceramic-forming metal oxide composition, and quenching the melt into a glass which is then formed into a preform of thin plate. The preform is soften and wire-drawn without causing crystallization in a furnace into a flexible elongated thin tape having a thickness of e.g. 40 to 60 .mu.m. The tape is heat-treated for crystallization to obtain the superconducting wire. The disclosure mentions mainly Bi Bi-Sr-Ca-Cu-O superconducting systems.

Method of producing superconducting ceramic wire and product

A superconducting ceramic wire is prepared from a superconducting ceramic-forming oxide composition by melting, the composition and quenching the melt to form a dense glass, which is soften and wire-drawn in a furnace. The resulting wire is heat-treated to form crystals and made into a superconducting ceramic wire. The wire has a flexibility and remarkable superconductivity which can further be improved by applying pressure to be made more dense and repeating the heat-treatment.

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Yokohama, Japan

Takashi Kohgo