Abstract: An chromatic dispersion compensator according to the invention is composed of a wavelength converter for converting a wavelength of a lightwave carrying an input signal into a conversion wavelength, a wavelength dispersion medium for giving different chromatic dispersion according to each wavelength to optical signal of the conversion wavelength output from the wavelength converter, a photodetector for converting optical signal of the conversion wavelength output from the chromatic dispersion medium into an electric signal, and a controller for controlling the conversion wavelength for a predetermined component in the output of the photodetector. In optical receivers, input signal light is transmitted through the above chromatic dispersion compensator and then demodulated into a data.

Abstract: The coupled waveguide structure comprises first and second rectangular waveguides, disposed closely. The aspect ratio of the first waveguide is substantially inverse in number to that of the second waveguide.

Abstract: An optical add/drop multiplexer device which is capable of extracting or inserting optical signals of arbitrary wavelength and having a wavelength selection characteristic with a narrow bandwidth, and which is compact in size and highly reliable. The device is formed by a substrate member; a plurality of optical waveguides, formed over the substrate member in layers with a prescribed interval along a direction perpendicular to a plane of the substrate member, each optical waveguide having a portion arranged in parallel and in proximity to an adjacent optical waveguide to form a coupling section; and a diffraction grating member, provided at the coupling section and having a prescribed period along a light propagation direction, for reflecting light signals with a specific wavelength among light signals entered from one of adjacent optical waveguides to another one of the adjacent optical waveguides.

Abstract: An at least monoaxially stretched polypropylene film made of a composition comprising a crystalline polypropylene and a monocyclic olefin polymer (e.g. a polycyclobutene or a polycyclopentene), wherein the content of the monocyclic olefin polymer is 0.1-1,000 ppm by weight.The polypropylene film is superior not only in transparency but also in image clarity by which an image is clearly seen through the film.The polypropylene film, when further comprising talc having an average particle diameter of 0.1-10 .mu.m in an amount of 50-4,000 ppm by weight, can prevent the surface roughening or edge roughening of sheet during the sheet formation conducted before stretched film production.The polypropylene film, when further comprising an anti-blocking agent and a polyethylene together, can prevent the generation of voids caused by the anti-blocking agent.

Abstract: Disclosed is a novel spirooxazine compound having excellent durability which changes into a colored form upon irradiation with the light containing ultraviolet rays such as of sunrays or the light from a mercury lamp, the change being reversible.

Abstract: A photochromic compound of the present invention is a spiroxazine compound represented by the following formula: ##STR1## wherein R.sup.1 to R.sup.3 represent a monovalent organic group such as alkyl group, Y represents a fused heterocyclic aromatic hydrocarbon group or an unsaturated heterocyclic group if R.sup.1 and R.sup.2 are both methyl groups, and represents an aromatic hydrocarbon group or unsaturated heterocyclic group if R.sup.1 and R.sup.2 are other than the above mentioned. This compound shows an excellent photochromic characteristics even at high temperatures not less than ambient temperature.

Abstract: Disclosed is a bipolar membrane comprising a cation-exchange membrane in which a cation-exchange group present at least at its adhered surface has been ion-exchanged with a heavy metal ion, which is adhered closely to an anion-exchange membrane at a peel strength of not less than 0.2 kg f/25 mm, and having a water-splitting current efficiency of not less than 80% and a water-splitting membrane potential of not more than 2.0 V.

Abstract: There is disclosed a vertical mill comprising a rotatable table and rotatable grinding rollers disposed on the upper surface of the table near the outer periphery of the table. Raw material is supplied to the central portion of the table. A given grinding pressure is applied to each grinding roller to crush the raw material between the upper surface of the table and the outer surface of each grinding roller. Rotatable auxiliary rollers are arranged alternately with the grinding rollers on the upper surface of the table near the outer periphery of the table. The layer of the material caught by the grinding rollers are compacted by the outer surfaces of the auxiliary rollers. There is also disclosed a method of operating the vertical mill. The method consists in separating controlling the grinding pressures applied to the grinding rollers according to the loads on the grinding rollers.

Abstract: A kit for the administration of a radiopharmaceutical liquid composition has been developed, which includes a radiation-shielding injector accompanied with a syringe-type vial having a gasket therein, a seal cap and a plunger to be engaged with the gasket. The injector is made of a radiation-shielding tubular metal body covered with a plastic material having an exit at the bottom, the body being further provided with a lead glass window on its curved surface, a packing engaging the inside surface at one end of the body and a pair of wings having skid-proof ridges formed on at least one surface thereof, the wings being located at one end of the body. The body is so designed as to be shorter than the tubular portion of the syringe-type vial to be inserted therein, whereby the rear portion of the vial protrudes a little from the tubular body when the same is inserted into the body.

Abstract: A radiation-shielding container comprising an outer plastic tube, an inner radiation-shielding metal tube inserted into the outer tube and a top plastic cap accompanied with a plug made of a radiation-shielding metal on its back and a bottom plastic cap, wherein the top and the bottom caps attach to the uppermost and the lowermost edges, respectively of the plastic outer tube in a snap-on method or a screwed or threading method, have respectively a peripheral thin section on the curved surface and are so designed that they can not be removed from the outer tube unless the thin section of the cap is cut off or that the thin section is forcibly opened.

Abstract: A magneto-optical recording medium, which comprises a thin film constituted of an amorphous alloy (R.sub.x TM.sub.1-x).sub.1-y A.sub.y (where the element material R is at least one rare earth element, the element material TM at least one 3d transition metal and the element material A at least one semi-metal-semiconductor element) and having an easy axis of magnetization in a direction perpendicular to the film surface, the atomic ratio being 0.15.ltoreq.xx.ltoreq.0.35 and 0.00<y.ltoreq.0.20.

Abstract: Amorphous thin film with easy magnetization axis perpendicular to film surface for magneto-optical recording with low recording power and high S/N in reading signal is set forth. The medium is an alloy of heavy rare earth element and iron with substitution of some heavy rare earth elements by light rare earth element, and the preferable chemical formula of the thin film is (R.sub.z A.sub.1-z).sub.x Fe.sub.1-x, or [(R.sub.z A.sub.1-z).sub.y B.sub.1-y ].sub.x Fe.sub.1-x where R is a light rare earth element, A and B are heavy rare earth elements, and the atom ratios satisfy 0.15.ltoreq.x.ltoreq.0.35, 0.00<y<1.00, 0.00<z<1.00. Recording is effected by using Curie point, or magnetic compensation temperature, and reading of information is effected by using the Kerr effect.

Abstract: A magneto-optical recording medium having an easy axis of magnetization in a direction perpendicular to the film surface, characterized in that a readout medium layer, a reflection layer and a recording medium layer are sequentially disposed in a direction of the incidence of a reading-out light, thereby to increase a reproduced output.

Abstract: A magneto-optical recording and reproducing apparatus for recording information on a recording medium made of a magneto-optical recording material. The apparatus is provided with at least two lasers for carrying out simultaneously a combination of two functions of the apparatus such as recording-reproducing or reproducing-erasing or erasing-recording functions. The recording and erasing is effected optically by independent light beams. Provision is made for recording and erasing the information by light beam and by use of an application of magnetic fields of different coercive values. The lasers are modulated or not independently and an optical system is provided through which the write-in and readout takes place and focusing is in response to the reflected light from the record on the recording medium.

Abstract: A multi-layer magneto-optical recording medium is constructed by placing a transparent protective film upon a magneto-optical recording medium wherein the easy axis of magnetization is provided perpendicular to the film surface so as to make the direction of magnetization perpendicular thereto to take a binary code depending on whether the vertical direction thereof is upward or downward, and further by placing a metal film, of which melting point is lower than either said magneto-optical recording medium and said transparent protective film, upon said transparent protective film.The metal film is evaporated by a laser beam irradiated thereon in a manner to leave a portion thereof not evaporated to become a tracking guide, whereby reproducing a magneto-optical record free of disturbance on linear polarization.The metal film can be perforated to form pits by irradiation of a laser beam.