Abstract: A composition has a durability to a sterilization treatment using vapor under high temperature and pressure and capable of transmitting or absorbing light. The composition comprises a group A including 15 to 23 mol % of lanthanum oxide, 3 to 8 mol % of gadolinium oxide, 3 to 8 mol % of tantalum oxide, and 8 mol % or less of yttrium oxide; a group B including 30 to 45 mol % of boron oxide, 20 mol % or less of silicon oxide, and 20 mol % or less of germanium oxide; zero mol % of alkaline metal oxide or alkaline earth metal oxide; and a group D including 0.3 to 15 mol % of niobium oxide and 3 to 15 mol % of zirconium oxide. A mol % ratio A/B between the group A and group B is 80% or more, and a dissolving-out rate of metal ion of the composition is 0.002×10−6 mol/hour or less per square centimeter.

Abstract: The invention relates to a glass excellent in infrared absorption capability and corrosion resistance, and its fabrication process. A compound of divalent copper and a compound of a metal species for a network modifier oxide are introduced in a wet gel. Then, the wet gel is dipped in a dipping solution having a low solubility with respect to the compound of divalent copper and the compound of a metal species for a network modifier oxide for the precipitation in the wet gel of the divalent copper compound and the compound of a metal species for a network modifier oxide, followed by drying and firing. Thus, an infrared absorbing glass comprising 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide other than CuO is fabricated.

Abstract: A lightweight and homogeneous optical element exhibiting favorably weak birefringence and hygroscopicity as well as superior productivity and producing minimal chromatic aberrations is formed by using an organic-inorganic composite material having both the properties of a glass material and those of a plastic material. The optical element has at least one entrance refracting surface and at least one exit refracting surface. The optical element is formed from an organic-inorganic composite material having an inorganic phase dispersed in the three-dimensional network (matrix) of an organic phase.

Abstract: The invention relates to a glass excellent in infrared absorption capability and corrosion resistance, and its fabrication process. A compound of divalent copper and a compound of a metal species for a network modifier oxide are introduced in a wet gel. Then, the wet gel is dipped in a dipping solution having a low solubility with respect to the compound of divalent copper and the compound of a metal species for a network modifier oxide for the precipitation in the wet gel of the divalent-t copper compound and the compound of a metal species for a network modifier oxide, followed by drying and firing. Thus, an infrared absorbing glass comprising 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide other than CuO is fabricated.

Abstract: In a method of making a high-quality silica glass, a rare earth element that is a substance making a great contribution to the index of refraction is introduced therein together with aluminum for stabilizing the glass. An alkoxide of aluminum or its derivative is used as the starting material for preparing a boehmite sol. A salt of at least one element selected from rare earth elements or a solution in which the salt is dissolved and the boehmite sol are mixed with a silica sol, whereupon the sols are vitrified.

Abstract: A gradient-index optical element comprises SiO2, BaO, and TiO2 as essential components, and has a refractive index profile in its diametrical direction. The molar ratio of barium to silicon at the center of the element in its diametrical direction is limited to Ba/Si≧0.4. This gradient-index optical element has a small refractive index difference with reduced chromatic aberrations and, hence, is suitable for use with optical equipment.

Abstract: The invention provides a process of obtaining a gradient index type of optical element with profiles of first and second metal component concentrations by the sol-gel method. The process of fabricating a gradient index type of optical element comprises steps of dipping a silicon component-containing wet gel prepared by the sol-gel method in a solution containing an alkoxide of at least one metal component selected from a first group consisting of Ti, Nb, Ta, and Zr or a derivative thereof to thereby impart to the wet gel a concentration gradient with a concentration of the first metal component decreasing from a periphery to a center of the wet gel, allowing at least one metal component selected from a second group consisting of Ba, La, Y, Gd, Sr, Ca, and Zn to be dissolved out of the wet gel to thereby impart to the wet gel a concentration gradient with a concentration of the second metal component increasing from the periphery to the center of the wet gel, and drying, and firing the wet gel.

Abstract: A porous body containing a silicon component as a starting material of optical element is immersed in a solution containing hydrofluoric acid, taken out from the solution and immersed in a solution containing a metal alkoxide containing a first metal component except silicon or a derivative thereof so that the porous body contains the first metal component in such a concentration gradient that the concentration of the first metal component decreases from a periphery of the porous body toward a center of the porous body. Hydrofluoric acid breaks glass bonds of the porous body, so that the concentration of the first metal component can be securely distributed in a desired gradient. Drying and sintering of the porous body enables producing, for example, a glass having a metal component concentration concavely distributed in its radial direction which is excellent in chromatic aberration suppressing capability.

Abstract: A method which enables an optical element having a large refractive index difference and a stabilized refractive index distribution to be produced in a short time. When a gel prepared by a sol-gel method is immersed in a solution containing at least one substance selected from the group consisting of an organic solvent, water, an acid, and an alkali, or in a solution having a metal salt dissolved in the at least one substance selected from the above group, a component eluted into the solution from the gel and/or a foreign substance which is produced or mixed in the solution during the solution immersing step is removed, and a component diffused into the gel from the solution is supplemented to the solution.

Abstract: A connector comprises a combination of a plug connector and a receptacle connector. The plug connector has a plug insulator provided with first plug-side engaging portions formed on opposite side walls thereof, and at least one second plug-side engaging portion formed on a part of the plug insulator that is parallel to a width direction of the plug insulator. The receptacle connector has a receptacle insulator provided with first receptacle-side engaging portions formed on opposite side walls thereof to be engaged with the first plug-side engaging portions, and at least one second receptacle-side engaging portion formed on a part of the receptacle insulator that is parallel to a width direction of the receptacle insulator to be engaged with the second plug-side engaging portion.

Abstract: A connector is connected to a cable composed of a plurality of electric wires, each of which comprises a metal wire covered with an insulator, and a sheath provided with an opening formed at its terminal end and covering the electric wires with one end portions of the electric wires projecting from the opening. The connector comprises an insulating base member, a plurality of conductive contact elements fixedly supported in the base member, and an insulating cover member removably coupled to the base member and covering terminal portions of the contact elements respectively connected to the metal wires. The cover member comprises an electric wire positioning portion for holding terminal ends of the one end portions of the electric wires so that the terminal ends confront the contact elements corresponding thereto, respectively, and a cable holding portion for holding the cable at an end portion of the sheath adjacent the opening.

Abstract: A semiconductor light emitting element comprising plural semiconductor layers inclusive of a light emitting part having a pn junction, which are laminated on a crystal substrate, wherein a first semiconductor layer, having a carrier concentration of not more than 5.times.10.sup.17 cm.sup.-3 and a band gap of not less than the energy of the light emitted from the light emitting part, is formed in the passage of the light emitted from the light emitting part toward the substrate side, and a second semiconductor layer, having a carrier concentration of not more than 5.times.10.sup.17 cm.sup.-3 and a band gap of not greater than the energy of the light emitted from the light emitting part, is formed behind (when seen from the passage of the light) the first layer. According to the present invention, sub-peak wavelength light emission can be suppressed to a satisfactory degree.

Abstract: An electrical connector has an insulator with a base portion, a main surface, and a mating portion formed on the main surface. A pair of blocks are formed at opposite ends of the base portion. Each block has a receiving surface parallel to an installation surface perpendicular to the main surface. The installation surface makes contact with a surface of a printed circuit board when the electrical connector is mounted on the printed circuit board. A plurality of electroconductive contacts are disposed on the mating portion. An electroconductive shell is attached to the base portion for surrounding the mating portion. A pair of flanges are formed at opposite ends of the shell and are received by the receiving surfaces of the blocks. A pair of electroconductive hook lugs are attached to the blocks. A pair of electroconductive holding members are mounted on side surfaces of the blocks and have portions extending in a plane including the installation surfaces.