Abstract: Provided is an optical glass having a composition including, by mol %: 0% to 15 % B2O3; 25% to 40% P2O5, the total content of B2O3 and P2O5 being 35% to 45%; 0% to 10% Al2O3; 5% to 15% Li2O; 0% to 15% Na2O; 0% to 5% K2O; 0% to 35% MgO; 0% to 35% CaO, the total content of MgO and CaO being 20% or more; 0% to 5 % ZnO; 0% to 3% ZrO2; 0% to 3% Y2O3; 0% to 3% La2O3; and 0% to 3% Gd2O3. The composition does not contain SrO and BaO.

Abstract: A relay optical system 20 for a rigid endoscope includes a lens fixing frame 21 and a plurality of lenses 22. The lens fixing frame 21 has a plurality of tubular bodies 26. The plurality of tubular bodies 26 are joined coaxially to each other. The plurality of lenses 22 are located at positions other than a joint position jp of the tubular bodies 26 in an axis direction of the lens fixing frame 21. The plurality of lenses 22 are located in the lens fixing frame 21 so as to have a coincident optical axis. The plurality of lenses 22 do not include a cemented lens.

Abstract: A flexible endoscope of the present invention includes a catheter portion and a connection plug. The catheter portion includes an image guide, a light guide, and a catheter tube that surrounds the image guide and the light guide in a longitudinal direction, and the connection plug includes a hollow cover that accommodates the proximal end of the catheter tube, a flexible tube that protrudes from the hollow cover and through which the catheter tube is passed, a first connection terminal that is connected to the light guide extending from the proximal end of the catheter tube, and a second connection terminal that is connected to the image guide extending from the proximal end of the catheter tube. The image guide and the light guide are slidable inside the catheter tube, and at least one of the image guide and the light guide is arranged curved inside the hollow cover of the connection plug.

Abstract: Provided is an optical fiber illumination device in which optical fibers produced without using a special method is used and the amount of light emitted from the side surface is improved. An optical fiber illumination device 1 includes: an optical fiber bundle 10 having a plurality of optical fibers, a resin jacket 101 that covers a bundle of the plurality of optical fibers and emits light, a first end, and a second end, the first end and the second end being polished; and a first light source placed close to the first end so as to emit light in a range of angles larger than an angular aperture of the plurality of optical fibers toward the optical fiber bundle.

Abstract: The multicomponent oxide glass has a composition including: 45-53 mol % SiO2; 22-30 mol % B2O3; 5-9 mol % Al2O3; 0.02-0.10 mol % Sb2O3; 0-18 mol % Li2O; 0-18 mol % Na2O; 0-18 mol % K2O; 0-13 mol % MgO; 0-13 mol % CaO; 0-13 mol % BaO; and 0-13 mol % ZnO. When the total content of Li2O, Na2O, and K2O is X mol % and the total content of MgO, CaO, BaO, and ZnO is Y mol %, 11?X?18 and 14?X+Y?24 hold, and the value of ?OH calculated from ?OH=?/t, where ? represents a height of an absorption peak due to OH groups, observed in a range of 3400 cm?1 to 3800 cm?1 of an infrared absorption spectrum in no unit and t represents a thickness of the glass in cm, is 4 cm?1 or more.

Abstract: Provided is an X-ray shielding glass having high shielding capability against X-rays with a tube voltage of 150 kV or less. The X-ray shielding glass has a composition including: 15 mass % to 25 mass % B2O3; 7 mass % to 50 mass % La2O3; 7 mass % to 50 mass % Gd2O3; 10 mass % to 25 mass % WO3; 0 mass % to 7 mass % SiO2; 0 mass % to 10 mass % ZrO2; 0 mass % to 8 mass % Nb2O5; 0 mass % to 10 mass % Ta2O5; 0 mass % to 5 mass % Bi2O3; 0 mass % to 3 mass % CeO2; and 0 mass % to 1 mass % Sb2O3, wherein the glass contains no ZnO, the total content of La2O3 and Gd2O3 is 45 mass % to 65 mass %, and when the thickness of the glass is 3 mm, the transmittance of the glass to an X-ray from an X-ray tube with a tube voltage of 60 kV is 0.0050% or less, and the transmittance of the glass to an X-ray from an X-ray tube with a tube voltage of 100 kV is 0.1500% or less.

Abstract: Provided is a high-quality lithium phosphorus complex oxide powder. The lithium phosphorus complex oxide powder comprises Li1+xMIIIxMIV2?x(PO4)3 (0?x?1, MIII represents an element selected from Al, Sc, Cr, Fe, Ga, and In, and MIV represents an element selected from Si, Ti, Ge, and Zr) and has a concentration of Zn as an impurity of less than 100 ppm.

Abstract: A relay optical system 20 for a rigid endoscope comprises a lens fixing frame 21 and a plurality of lenses 22. The lens fixing frame 21 has a plurality of tubular bodies 26. The plurality of tubular bodies 26 are joined coaxially to each other. The plurality of lenses 22 are located at positions other than a joint position jp of the tubular bodies 26 in an axis direction of the lens fixing frame 21. The plurality of lenses 22 are located in the lens fixing frame 21 so as to have a coincident optical axis. The plurality of lenses 22 do not include a cemented lens.

Abstract: Provided is a high-quality lithium phosphorus complex oxide powder. The lithium phosphorus complex oxide powder comprises Li1+xMIIIxMIV2?x(PO4)3 (0?x?1, MIII represents an element selected from Al, Sc, Cr, Fe, Ga, and In, and MIV represents an element selected from Si, Ti, Ge, and Zr) and has a concentration of Zn as an impurity of less than 100 ppm.

Abstract: An optical glass is provided which does not contain components negatively affecting the environment as environmental loads, and is less colored while having a refractive index maintained moderately high. The optical glass has a composition including, in % by mass, 30% or more and 47% or less of SiO2, 0% or more and 10% or less of B2O3, 3% or more and 12% or less of Na2O, 0% or more and 5% or less of Li2O, 0% or more and 3.8% or less of CaO, 28% or more and 43% or less of BaO, 3% or more and 16% or less of ZnO, 0% or more and 8% or less of ZrO2, 0% or more and 15% or less of La2O3, where Sb2O3 is excluded from the composition, wherein the optical glass does not contain any of PbO, As2O3, and K2O.

Abstract: The present disclosure is to provide a method of producing a LTP or LATP crystal particle that has reduced impurity contamination, high crystallinity, and excellent dispersibility. The method of producing a LTP or LATP crystal particle according to the present disclosure includes: preparing glass containing, in molar ratio, 1+x of Li2O, where 0?x?1, x of Al2O3, 4?2x of TiO2, 3+y of P2O5, where 1?y?4, and from more than y to less than 3y of ZnO; subjecting, after the preparation of glass, the glass to thermal treatment for crystallization; and selectively eluting a substance other than a LTP or LATP crystal through acid treatment.

Abstract: Provided is an image guide fiber that improves image quality while preventing a manufacturing problem. The image guide fiber according to the present disclosure has a numerical aperture NA in the range of 0.70 to 0.90. A linear thermal expansion coefficient difference ??, which is a value obtained by subtracting a linear thermal expansion coefficient ?2 at from 100 to 300° C. of clad glass, from a linear thermal expansion coefficient ?1 at from 100 to 300° C. of core glass, is in the range of ?3×10?7° C. to 15×10?7/° C. A glass-transition temperature Tg1 of the core glass is higher than a glass-transition temperature Tg2 of the clad glass. A core occupancy area ratio is 25% or more. A pixel density is 0.1 pixel/?m2 or more.

Abstract: Provided is an image guide fiber that improves image quality while preventing a manufacturing problem. The image guide fiber according to the present disclosure has a numerical aperture NA in the range of 0.70 to 0.90. A linear thermal expansion coefficient difference ??, which is a value obtained by subtracting a linear thermal expansion coefficient ?2 at from 100 to 300° C. of clad glass, from a linear thermal expansion coefficient ?1 at from 100 to 300° C. of core glass, is in the range of ?3×10?7/° C. to 15×10?7/° C. A glass-transition temperature Tg1 of the core glass is higher than a glass-transition temperature Tg2 of the clad glass. A core occupancy area ratio is 25% or more. A pixel density is 0.1 pixel/?m2 or more.

Abstract: The present disclosure is to provide a method of producing a LTP or LATP crystal particle that has reduced impurity contamination, high crystallinity, and excellent dispersibility. The method of producing a LTP or LATP crystal particle according to the present disclosure includes: preparing glass containing, in molar ratio, 1+x of Li2O, where 0?x?1, x of Al2O3, 4?2x of TiO2, 3+y of P2O5, where 1?y?4, and from more than y to less than 3y of ZnO; subjecting, after the preparation of glass, the glass to thermal treatment for crystallization; and selectively eluting a substance other than a LTP or LATP crystal through acid treatment.

Abstract: To provide an optical system that lengthens the lifetime of a fiber, an optical system 13 guides light beams emitted from a plurality of light emitting parts ep into a single optical fiber 12, the plurality of light emitting parts ep are arranged to be aligned along a first direction d1, and the optical system 13 allows the light beams emitted from the plurality of light emitting parts ep to have different light collection centers which are offset from each other at least in a second direction d2.

Abstract: Provided is an optical glass having low specific gravity, low abrasion degree, and high devitrification-proof stability, as well as a preform for precision press molding and an optical element which use such an optical glass. The optical glass has a composition including, in cationic % expression, P5+: 36 to 40%, Al3+: 11 to 16%, Mg2+: 11 to 19%, Ca2+: greater than 0% and 2% or less, Sr2+: 0 to 4%, Ba2+: 25 to 31%, Zn2+: 0% or more and less than 2.4%, and Y3+: 2 to 7%, a total amount of Zn2+ and Y3+ (Zn2++Y3+) being 3 to 7%. The composition also includes, in anionic % expression, O2?: 74 to 78%, and F?: 22 to 26%. Li+, Na+, K+, La3+, and Gd3+ are not included. The optical glass further has a refractive index (nd) of 1.58 to 1.60 and an Abbe number (?d) of 67 to 69.

Abstract: Provided is a medium-refractive-index low-dispersion optical glass that may be precision press-molded, that has a high water resistance, and that has a low specific gravity, as well as a preform for precision press molding and an optical element which use such an optical glass. The optical glass has a composition including, in % by mass, SiO2: 35 to 55%, B2O3: 12 to 27%, Al2O3: 6 to 16%, Li2O: 5 to 12%, MgO: 0 to 10%, CaO: 5 to 17%, ZrO2: 0 to 7%, La2O3: 0 to 7%, ZnO: 0 to 5%, TiO2: 0 to 5%, Nb2O5: 0 to 5%, and Ta2O5: 0 to 5%. SrO and BaO are not included.

Abstract: A method of manufacturing a light-emitting device including a light-emitting element mounted on a substrate and sealed with a glass. The method includes heating the glass by a first mold that is heated to a temperature higher than a yield point of the glass, the glass contacting the first mold, and pressing the glass against the light-emitting element mounted on the substrate supported by a second mold to seal the light-emitting element with the glass.