Abstract: The glass composition according to the present invention is a glass composition including SiO2, B2O3, Al2O3, an alkaline-earth metal oxide and another metal oxide. When an average thermal expansion coefficient of the glass composition in a temperature range of 0° C. to T° C. is expressed as CTE (T), a relationship of (17.1×10?3×T+25.4)×10?7/° C.?CTE (T)?(17.1×10?3×T+31.4)×10?7/° C. is satisfied in a temperature range of 0° C. to 100° C.

Abstract: The present invention provides a glass composition that allows holes with a circular contour and a smooth inner wall to be formed by a collective micro-hole-forming process using a combination of modified portion formation by ultraviolet laser irradiation and etching, the glass composition being adapted for practical continuous production. The present invention relates to a glass for laser processing, the glass including a metal oxide serving as a coloring component, the glass having a glass composition including, in mol %: 45.0%?SiO2?68.0%; 2.0%?B2O3?20.0%; 3.0%?Al2O3?20.0%; 0.1%?TiO2?5.0%; and 0%?ZnO?9.0%, wherein a relationship of 0?Li2O+Na2O+K2O<2.0% is satisfied.

Abstract: The present invention provides a low-alkali or alkali-free glass for laser processing, the glass reducing occurrence of laser irradiation-induced cracks and allowing formation of circular through holes. The present invention relates to the glass for laser processing, the glass having a glass composition including, in mol %: 45.0%?SiO2?70.0%; 2.0%?B2O3?20.0%; 3.0%?Al2O3?20.0%; 0%?ZnO?9.0%; and (I) 0.1%?CuO?2.0% and 0%?TiO2?15.0%; or (II) 0.1%?TiO2<5.0% and 0%?CuO<0.1%, wherein, in the case of (II), a metal oxide serving as a coloring component is further included, a relationship of 0?Li2O+Na2O+K2O<2.0% is satisfied, either of principal surfaces of the glass has a layer containing fine particles, and the fine particles have an average particle diameter of 10 nm or more and less than 1.0 ?m.

Abstract: The present invention provides a glass composition that allows holes with a circular contour and a smooth inner wall to be formed by a collective micro-hole-forming process using a combination of modified portion formation by ultraviolet laser irradiation and etching, the glass composition being adapted for practical continuous production. The present invention relates to a glass for laser processing, the glass having a glass composition including, in mol %: 45.0%?SiO2?70.0%; 2.0%?B2O3?20.0%; 3.0%?Al2O3?20.0%; 0.1%?CuO?2.0%; 0%?TiO2?15.0%; and 0%?ZnO?9.0%, wherein a relationship of 0?Li2O+Na2O+K2O<2.0% is satisfied.

Abstract: The present invention provides a glass composition that allows holes with a circular contour and a smooth inner wall to be formed by a collective micro-hole-forming process using a combination of modified portion formation by ultraviolet laser irradiation and etching, the glass composition being adapted for practical continuous production. The present invention relates to a glass for laser processing, the glass including a metal oxide serving as a coloring component, the glass having a glass composition including, in mol %: 45.0%?SiO2?68.0%; 2.0%?B2O3?20.0%; 3.0%?Al2O3?20.0%; 0.1%?TiO2?5.0%; and 0%?ZnO?9.0%, wherein a relationship of 0?Li2O+Na2O+K2O<2.0% is satisfied.

Abstract: The present invention provides a glass composition that allows holes with a circular contour and a smooth inner wall to be formed by a collective micro-hole-forming process using a combination of modified portion formation by ultraviolet laser irradiation and etching, the glass composition being adapted for practical continuous production. The present invention relates to a glass for laser processing, the glass having a glass composition including, in mol %: 45.0%?SiO2?70.0%; 2.0%?B2O3?20.0%; 3.0%?Al2O3?20.0%; 0.1%?CuO?2.0%; 0%?TiO2?15.0%; and 0%?ZnO?9.0%, wherein a relationship of 0?Li2O+Na2O+K2O<2.0% is satisfied.

Abstract: An erecting equal-magnification lens array plate includes a stack of a first lens array plate provided with a plurality of first lenses arranged on a first surface and a plurality of second lenses arranged on a second surface, and a second lens array plate provided with a plurality of third lenses arranged on a third surface and a plurality of fourth lenses arranged on a fourth surface. The erecting equal-magnification lens array plate is provided with a first light shielding wall provided upright to surround the first lens, and a second light shielding wall provided upright to surround the fourth lens. An area on the first surface of the first lens array plate outside the effective region of the first lenses is roughened.

Abstract: A clad glass composition that is excellent in devitrification resistance and that prevents the whole mother glass rod from devitrifying by preventing a core glass composition from devitrifying in forming a mother glass rod using a concentric crucible drawing method, is provided. The clad glass composition forms a clad of a mother glass rod for a gradient-index rod lens having a core/clad structure.

Abstract: An erecting equal-magnification lens array plate includes a stack of a first lens array plate provided with a plurality of first lenses arranged on a first surface and a plurality of second lenses arranged on a second surface, and a second lens array plate provided with a plurality of third lenses arranged on a third surface and a plurality of fourth lenses arranged on a fourth surface. The erecting equal-magnification lens array plate is provided with a first light shielding wall provided upright to surround the first lens, and a second light shielding wall provided upright to surround the fourth lens. An area on the first surface of the first lens array plate outside the effective region of the first lenses is roughened.

Abstract: The present invention provides a clad glass composition that is excellent in devitrification resistance and that prevents the whole mother glass rod from devitrifying by preventing a core glass composition from devitrifying in forming a mother glass rod using a concentric crucible drawing method. The clad glass composition forms a clad of a mother glass rod for a gradient-index rod lens having a core/clad structure. The clad glass composition includes the following components, indicated by mol %: 45 to 65% SiO2; 0.5 to 10% TiO2; 0 to 15% B2O3; 0 to 7% Al2O3; 0.1 to 10% Bi2O3; 0 to 5% Li2O; 5 to 30% Na2O; 0 to 10% K2O; 0 to 15% MgO; 0 to 10% CaO; 0 to 10% SrO; 0.

Abstract: A glass composition suitable for producing a graded-refractive-index rod lens having an angular aperture of 16-20° without containing lead or thallium and a graded-refractive-index rod lens produced from the composition are provided. The composition is a base glass composition for graded-refractive-index rod lenses, characterized by comprising, in terms of % by mole, 20?SiO2?52, 1?B2O3?30, 12?Li2O?18, 8?Na2O?15, 0?MgO?15, 0?SrO?10, 0?BaO?10, 0?ZnO?15, 0?TiO2?15, 0?Nb2O5?5, 0?Ta2O5?5, and 3<Bi2O3?13, provided that 45?SiO2+B2O3?65, 9?MgO+ZnO+TiO2?25, and 0?Nb2O5+Ta2O5?5, and by containing substantially no lead and substantially no thallium.

Abstract: A gradient-index rod lens is provided that is excellent in yield. The gradient-index rod lens has a core/clad structure and is obtained by providing a mother glass rod, which includes a core glass mother composition and a clad glass mother composition, with a refractive index distribution through ion exchange. The clad and the core each contains an alkali metal oxide but are substantially free from lead. The clad and the core each contains an alkali metal oxide and has a basic composition including components other than the alkali metal oxide, but they are different from each other in the basic composition. The clad glass mother composition has a higher thermal expansion coefficient and glass-transition temperature than those of the core glass mother composition. The difference of the thermal expansion coefficient between the clad glass mother composition and the core glass mother composition is larger than 2×10?7/° C. but smaller than 20×10?7/° C.

Abstract: It is an object of the present invention to provide a clad glass composition for graded-index rod lens for covering, during manufacturing, a preform glass composition lens of a graded-index rod lens that does not include PbO, in which the composition substantially does not include PbO, and expressed in mol % includes SiO2: 45 to 65, Na2O: 3 to 30, K2O: 0 to 10, MgO: 0 to 15, BaO: 0 to 20, where Na2O+K2O: 3 to 35 and MgO+BaO: 0 to 25, and furthermore includes B2O3: 0 to 15, ZnO: 0 to 10, TiO2: 0 to 10, Y2O3: 0 to 7, ZrO2: 0 to 7, Nb2O5: 0 to 7, In2O3: 0 to 7, La2O3: 0 to 7, Ta2O5: 0 to 10, where B2O3+ZnO+TiO2+Y2O3+ZrO2+Nb2O5+In2O3+La2to 20, and a content of at least one of TiO2 and La2O3 is substantially 0 mol %.

Abstract: A gradient-index rod lens is provided that is excellent in yield. The gradient-index rod lens has a core/clad structure and is obtained by providing a mother glass rod, which includes a core glass mother composition and a clad glass mother composition, with a refractive index distribution through ion exchange. The clad and the core each contains an alkali metal oxide but are substantially free from lead. The clad and the core each contains an alkali metal oxide and has a basic composition including components other than the alkali metal oxide, but they are different from each other in the basic composition. The clad glass mother composition has a higher thermal expansion coefficient and glass-transition temperature than those of the core glass mother composition. The difference of the thermal expansion coefficient between the clad glass mother composition and the core glass mother composition is larger than 2×10?7/° C. but smaller than 20×10?7/° C.

Abstract: The present invention provides a clad glass composition that is excellent in devitrification resistance and that prevents the whole mother glass rod from devitrifying by preventing a core glass composition from devitrifying in forming a mother glass rod using a concentric crucible drawing method. The clad glass composition forms a clad of a mother glass rod for a gradient-index rod lens having a core/clad structure. The clad glass composition includes the following components, indicated by mol %: 45 to 65% SiO2; 0.5 to 10% TiO2; 0 to 15% B2O3; 0 to 7% Al2O3; 0.1 to 10% Bi2O3; 0 to 5% Li2O; 5 to 30% Na2O; 0 to 10% K2O; 0 to 15% MgO; 0 to 10% CaO; 0 to 10% SrO; 0.

Abstract: It is an object of the present invention to provide a clad glass composition for graded-index rod lens for covering, during manufacturing, a preform glass composition lens of a graded-index rod lens that does not include PbO, in which the composition substantially does not include PbO, and expressed in mol % includes SiO2: 45 to 65, Na2O: 3 to 30, K2O: 0 to 10, MgO: 0 to 15, BaO: 0 to 20, where Na2O+K2O: 3 to 35 and MgO+BaO: 0 to 25, and furthermore includes B2O3: 0 to 15, ZnO: 0 to 10, TiO2: 0 to 10, Y2O3: 0 to 7, ZrO2: 0 to 7, Nb2O5: 0 to 7, In2O3: 0 to 7, La2O3: 0 to 7, Ta2O5: 0 to 10, where B2O3+ZnO+TiO2+Y2O3+ZrO2+Nb2O5+In2O3+La2O3+Ta2O5: 0 to 20, and a content of at least one of TiO2 and La2O3 is substantially 0 mol %.