Abstract: In a press molding apparatus for press molding a plurality of glass materials into a plurality of glass optical elements by the use of a pressing mold including upper and lower molds each of which has a plurality of molding surfaces, at least one of the upper and the lower molds is a heat generator within which heat is generated when the heat generator is subjected to a high-frequency induction heating by an induction heating coil. The heat generator having a plurality of shape-processed portions (130) produced by partially processing a shape of the heat generator in order that a temperature distribution of the heat generator is adjusted. The apparatus simultaneously press forms, into the glass optical elements, the glass materials supplied between the molding surfaces of the upper and the lower molds which are subjected to the high-frequency induction heating.

Abstract: In a press molding apparatus for press molding a plurality of glass materials into a plurality of glass optical elements by the use of a pressing mold including upper and lower molds each of which has a plurality of molding surfaces, at least one of the upper and the lower molds is a heat generator within which heat is generated when the heat generator is subjected to a high-frequency induction heating by an induction heating coil. The heat generator having a plurality of shape-processed portions (130) produced by partially processing a shape of the heat generator in order that a temperature distribution of the heat generator is adjusted. The apparatus simultaneously press forms, into the glass optical elements, the glass materials supplied between the molding surfaces of the upper and the lower molds which are subjected to the high-frequency induction heating.

Abstract: A press molding apparatus includes upper and lower mother molds 102 and 104. Each of the mother molds 102 and 104 has four molding surfaces arranged in a single line and satisfies the relationship given by L×?×?T/t<0.0008, where L represents the length, t, the thickness, ?, the thermal expansion coefficient, and ?T, the temperature difference between both ends in the thickness direction during induction heating. The press molding apparatus may include a pressing mold set including upper mother molds 102a and 102b attached to a common fixed shaft 118 through upper supporting shafts 110a and 110b and lower mother molds 104a and 104b driven by a common drive shaft 120 through lower supporting shafts 112a and 112b. The upper mother molds 102a and 102b and the lower mother molds 104a and 104b are collectively heated by induction heating coils 122 and 124, respectively.

Abstract: A press molding apparatus includes upper and lower mother molds 102 and 104. Each of the mother molds 102 and 104 has four molding surfaces arranged in a single line and satisfies the relationship given by L×?×?T/t<0.0008, where L represents the length, t, the thickness, ?, the thermal expansion coefficient, and ?T, the temperature difference between both ends in the thickness direction during induction heating. The press molding apparatus may include a pressing mold set including upper mother molds 102a and 102b attached to a common fixed shaft 118 through upper supporting shafts 110a and 110b and lower mother molds 104a and 104b driven by a common drive shaft 120 through lower supporting shafts 112a and 112b. The upper mother molds 102a and 102b and the lower mother molds 104a and 104b are collectively heated by induction heating coils 122 and 124, respectively.

Abstract: A press molding apparatus includes upper and lower mother molds 102 and 104. Each of the mother molds 102 and 104 has four molding surfaces arranged in a single line and satisfies the relationship given by L×&agr;×&Dgr;T/t<0.0008, where L represents the length, t, the thickness, &agr;, the thermal expansion coefficient, and &Dgr;T, the temperature difference between both ends in the thickness direction during induction heating. The press molding apparatus may include a pressing mold set including upper mother molds 102a and 102b attached to a common fixed shaft 118 through upper supporting shafts 110a and 110b and lower mother molds 104a and 104b driven by a common drive shaft 120 through lower supporting shafts 112a and 112b. The upper mother molds 102a and 102b and the lower mother molds 104a and 104b are collectively heated by induction heating coils 122 and 124, respectively.

Abstract: In a press molding apparatus for press molding a plurality of glass materials into a plurality of glass optical elements by the use of a pressing mold including upper and lower molds each of which has a plurality of molding surfaces, at least one of the upper and the lower molds is a heat generator within which heat is generated when the heat generator is subjected to a high-frequency induction heating by an induction heating coil. The heat generator having a plurality of shape-processed portions (130) produced by partially processing a shape of the heat generator in order that a temperature distribution of the heat generator is adjusted. The apparatus simultaneously press forms, into the glass optical elements, the glass materials supplied between the molding surfaces of the upper and the lower molds which are subjected to the high-frequency induction heating.

Abstract: A process for producing a polarizing glass containing shape-anisotropic metallic particles dispersed in an oriented state therein, which comprises drawing a glass preform containing metallic halide particles dispersed therein while its viscosity being held above 2×106, but below 7×107 poises; and subjecting the drawn glass to a reducing treatment so that a part or all of the metallic halide particles are reduced to metallic particles, which process enables it to produce a polarizing glass with a high yield from a starting material of a glass containing metallic halide particles, while avoiding glass breakage or fracture during elongation as well as preventing the elongated metallic halide particles from returning to a spherical shape.

Abstract: Disclosed are a polarizing glass comprising a glass layer(s) which contains shape-anisotropic metallic particles dispersed therein in an oriented state and a base glass which causes substantially no light scattering, said glass layer being provided on a part or whole of at least one of faces of said base glass, which has polarizing properties comparable to conventional counterparts, a largely decreased transmission loss and a strength acceptable to practical use. Processes for the production of the polarizing glass are also disclosed.

Abstract: A process for producing a polarizing glass containing shape-anisotropic metallic particles dispersed in an oriented state therein, which comprises drawing a glass preform containing metallic halide particles dispersed therein while its viscosity being held above 2.times.10.sup.6, but below 7.times.10.sup.7 poises; and subjecting the drawn glass to a reducing treatment so that a part or all of the metallic halide particles are reduced to metallic particles, which process enables it to produce a polarizing glass with a high yield from a starting material of a glass containing metallic halide particles, while avoiding glass to breakage or fracture during elongation as well as preventing the elongated metallic halide particles from returning to a spherical shape.

Abstract: A composite slab laser medium provided with a non-doped layer containing substantially no laser active materials and a first and second doped layers provided at both sides of the non-doped layer, respectively, in such a manner to hold the non-doped layer, each of which contains a laser active material. In this composite slab laser, a first surface of the first doped layer and a second surface of the second doped layer are in contact with the outside of the composite slab laser medium and are parallel with each other. Further, a laser oscillation or an optical amplification is performed by extracting a laser beam which travels in a zig-zag path undergoing total internal reflection at the first and second surfaces employed as alternate reflecting surfaces within the composite slab laser medium. Moreover, layers made of laser glass containing Nd.sub.2 O.sub.3 of from 3 to 9% by weight is employed as the doped layers. Furthermore, a total of the thicknesses of the first and second doped layers is of from 0.

Abstract: A laser medium for use in a slab laser having a light absorbing member provided in a region, wich is deviated from a zigzag path to be followed by a laser beam to be extracted therefrom and thus the laser beam does not pass through. Thereby, parasitic oscillation can be effectively suppressed, and laser oscillation and light amplification can be performed for a long period of time.

Abstract: A laser medium for use in a composite slab type laser, wherein laser active layers are divided in the longitudinal direction of the laser medium by removing at least a part of a region, which is deviated from a zigzag path and a laser beam to be extracted therefrom does not pass through. Thereby amplified spontaneous emission can be weaken and parasitic oscillation can be effectively suppressed, and further laser oscillation and light amplification can be performed for a long period of time.

Abstract: A single mode laser glass fiber showing excellent laser oscillation characteristics even at a short fiber length can be efficiently obtained using a phosphate laser glass with excellent laser characteristics.

Abstract: A Faraday rotation single-mode fiber having a high Verdet constant is disclosed, the core and the cladding of the fiber being made of a glass having the following composition: 26 to 38 mol % SiO.sub.2, 18 to 34 mol % B.sub.2 O.sub.3, 17 to 26 mol % Al.sub.2 O.sub.3, 18 to 32 mol % Tb.sub.2 O.sub.3, 0 to 5 mol % ZrO.sub.2, 0 to 5 mol % Ce.sub.2 O.sub.3, 0 to 5 mol % Pr.sub.2 O.sub.3, 0 to 5 mol % Dy.sub.2 O.sub.3 and 0 to 5 mol % Ho.sub.2 O.sub.3, provided that the total amount of the above ingredients is not less than 97 mol % and the total amount of Ce.sub.2 O.sub.3, Pr.sub.2 O.sub.3, Dy.sub.2 O.sub.3 and Ho.sub.2 O.sub.3 is 0 to 5 mol %.

Abstract: An optical glass comprising, in % by weight21.0 to 35.0% SiO.sub.2 ;0 to 10.0% B.sub.2 O.sub.3 ;0 to 4.0% Al.sub.2 O.sub.3 ;0.5 to 4.0% Li.sub.2 O;33.0 to 55.0% BaO+SrO+CaO+MgO+ZnO, with the proviso of19.0 to 45.0% BaO,0 to 15.0% SrO,0 to 20.0% CaO,0 to 5.0% MgO, and1.5 to 20.0% ZnO;8.0 to 23.0% La.sub.2 O.sub.3 ;2.0 to 8.0% ZrO.sub.2 ;0 to 10.0% TiO.sub.2 ;0 to 4.5% Nb.sub.2 O.sub.5 +Ta.sub.2 O.sub.5 ;0 to 5.0% WO.sub.3 ; and0 to 5.0% PbO.

Abstract: An optical glass comprising, in % by weight,18 to 38% P.sub.2 O.sub.5 ;3 to 30% Na.sub.2 O+K.sub.2 O,with the proviso of0 to 30% Na.sub.2 O and0 to 30% K.sub.2 O;8 to 65% PbO;1 to 45% Ta.sub.2 O.sub.5 ;0 to 20% Nb.sub.2 O.sub.5 ;0 to 15% TiO.sub.2 +WO.sub.3 ;0 to 25% BaO+CaO+ZnO+SrO+MgO,with the proviso of0 to 25% BaO,0 to 5% CaO,0 to 25% ZnO,0 to 20% SrO, and0 to 10% MgO;0 to 15% B.sub.2 O.sub.3 ;0 to 3% Li.sub.2 O;0 to 3% Al.sub.2 O.sub.3 ;0 to 3% ZrO.sub.2 ;0 to 3% Y.sub.2 O.sub.3 ;0 to 3% Gd.sub.2 O.sub.3 ; and0 to 3% La.sub.2 O.sub.3.

Abstract: Glass for use as an element of a Faraday rotator, consisting essentially of, by mol%, 10-30 Tb.sub.2 O.sub.3, 10-30 Al.sub.2 O.sub.3, and 30-80 SiO.sub.2 + B.sub.2 O.sub.3, with the proviso that SiO.sub.2 .gtoreq.15 and B.sub.2 O.sub.3 .gtoreq.10, and as optional components 0-5 ZrO.sub.2, 0-1 Sb.sub.2 O.sub.3, 0-1 As.sub.2 O.sub.3, and 0-2 AlF.sub.3. The glass has a large Verdet constant and a reduced absorption of light in the visible and infrared wavelength regions.