Abstract: A glass for a light guide fiber GA1 is used in a core of a fiber 10 of a light guide, and has a refractive index nd between 1.56 and 1.74. The glass for a light guide fiber GA1 has the following composition: (A) SiO2: 20 to 55 wt %, (B11) B2O3: 0 to 2.0 wt %, (B2) does not contain P2O5 and GeO2, (C1) (BaO+SrO+La2O3+Lu2O3+Ta2O3+Gd2O3+WO3): 39 to 46 wt %, (D1) ZnO: 4 to 16 wt %, (E) does not contain Al2O3, (F) does not contain ZrO2, (G) does not contain PbO and As2O3, (H1) (Na2O+K2O): 4 to 10 wt %, (I1) Sb2O3: 0.001 to 0.010 wt %, and (J1) (Na2SO4+K2SO4): 0.32 to 0.78 wt %.

Abstract: An endoscope includes an insertion portion including an image pickup section, an illumination section, and a light guide inserted inside the insertion portion, the light guide including a plurality of fibers made of a glass not containing lead, the plurality of fibers guiding illuminating light from a light source apparatus to the illumination section, the light guide having a numerical aperture of 0.46 to 0.90. A core glass of a fiber have a refractive index nd of 1.56 to 1.74, and a composition of (A) 20 to 55 wt % SiO2, (B1) 0 to 4.0 wt % B2O3, (B2) neither P2O5 nor GeO2 contained, (C) 25 to 72 wt % (BaO+SrO+La2O3+Lu2O3+Ta2O5+Gd2O3+WO3), (D) 0 to 30 wt % ZnO, (E) no Al2O3 contained, (F) no ZrO2 contained, (G) neither PbO nor As2O3 contained, (H) 0 to 15 wt % (Na2O+K2O), (I) 0 to 0.050 wt % Sb2O3 and (J) 0.26 to 1.63 wt % (Na2SO4+K2SO4).

Abstract: An immersion solution for a microscope, the immersion solution including a metal-halogeno complex anion containing bromine or iodine and one or more types of metal elements M selected from Sn, In, Bi, Sb, Zn and Al, and an imidazolium cation, a pyridinium cation, a pyrrolidinium cation or an ammonium cation. The immersion solution includes an ionic liquid that transmits light having a predetermined wavelength, has a refractive index of no less than 1.60 and is used for a fluorescence microscope.

Abstract: An endoscope includes: an insertion portion including a distal end portion, to be inserted into a subject; an observation optical system disposed in the insertion portion; an optical member configuring a part of an outer surface of the distal end portion, through which a photographing light to be incident into the observation optical system transmits; a first hydrophilic portion that is film-formed at least on a surface of the optical member; a second hydrophilic portion that is film-formed on a first surface of the distal end portion in which the optical member is disposed; and a third hydrophilic portion that is film-formed on a second surface separate from the first surface of the distal end portion.

Abstract: The invention provides a fabrication process for single-crystal optical devices wherein, in a processing step for a single-crystal optical device, at least one heating treatment is implemented at a temperature that is 0.50 times to less than 0.67 times as high as the melting point of a single-crystal material after a member is cut out of a matrix material for the single-crystal material having a melting point of greater than 2,000° C. to less than 2,900° C. and before an optical device assembling step.

Abstract: A fluorescence observation or fluorescence measuring system has at least one of a low-fluorescence objective lens including optical elements made of low-fluorescence glass, satisfying Condition (a) described below, a low-fluorescence immersion substance satisfying Condition (b) described below, and a low-fluorescence cover glass satisfying Condition (c) described below: BOB?/BOB?0.7??(a) BIM?/BIM?0.7??(b) BCG?/BCG?0.7??(c) where BOB?, BIM?, and BCG? are average intensity values of auto-fluorescence from the low-fluorescence objective lens, immersion substance, and cover glass, respectively, and BOB, BIM, and BCG are average intensity values of auto-fluorescence from a conventional objective lens, immersion substance, and cover glass, respectively, generally used.

Abstract: The fluorescence observation or fluorescence photometry system uses an optical base material having low autofluorescence and good adhesive property to cell. Said optical base material has the following optical characteristics: 1.3?nd?1.9 15??d?100 where nd represents refractive index in d line, and ?d represents Abbe number in d line; and, an optical instrument constituted for enabling a fluorescence observation and/or a fluorescence measurement is arranged. Thereby, a fluorescence observation or a fluorescence photometry system, and a fluorescence observation or a fluorescence photometry method in which sufficient signal obtained from a cell can be obtained as much as possible, and more accurate observation and measurement can be promoted is offered.

Abstract: A fluorescence observation or fluorescence metering-system includes a low-fluorescence specimen holding member used therein. The low-fluorescence specimen holding member satisfies a condition, BSG?/BSG?0.6, where BSG? is an average intensity value of auto-fluorescence from the low-fluorescence specimen holding member and BSG is an average intensity value of auto-fluorescence from a conventional specimen holding member generally used.

Abstract: An endoscope includes: an insertion portion including a distal end portion, to be inserted into a subject; an observation optical system disposed in the insertion portion; an optical member configuring a part of an outer surface of the distal end portion, through which a photographing light to be incident into the observation optical system transmits; a first hydrophilic portion that is film-formed at least on a surface of the optical member; a second hydrophilic portion that is film-formed on a first surface of the distal end portion in which the optical member is disposed; and a third hydrophilic portion that is film-formed on a second surface separate from the first surface of the distal end portion.

Abstract: The immersion oil has refractive index which is 1.70 or more, and is low autofluorescence. Preferably, the main ingredient is iodine compounds (diiodomethane), and a solid having a high refractive index such as sulfur and the like is dissolved or dispersed into the immersion oil. The production method of the immersion oil has a purification process, in which impurities are removed preferably by adsorbent, distillation or recrystallized. In the method of preservation of the immersion oil, it is always contacted with the adsorbent. The preservation container of the immersion oil contains an adsorbent which is always contacted with the immersion oil.

Abstract: A fluorescence observation or fluorescence measuring system has at least one of a low-fluorescence objective lens including optical elements made of low-fluorescence glass, satisfying Condition (a) described below, a low-fluorescence immersion substance satisfying Condition (b) described below, and a low-fluorescence cover glass satisfying Condition (c) described below: BOB?/BOB?0.7 ??(a) BIM?/BIM?0.7 ??(b) BCG?/BCG?0.7 ??(c) where BOB?, BIM?, and BCG? are average intensity values of auto-fluorescence from the low-fluorescence objective lens, immersion substance, and cover glass, respectively, and BOB, BIM, and BCG are average intensity values of auto-fluorescence from a conventional objective lens, immersion substance, and cover glass, respectively, generally used.

Abstract: In a connector including a contact and a housing holding the contact, a shell is coupled with the housing. The housing has a coupling portion to be coupled with a mating connector in a first direction. The contact has a contacting portion disposed in the coupling portion. The shell includes an opening edge defining an opening faced to the coupling portion and a guide portion disposed in the coupling portion to guide movement of the mating connector in the first direction.

Abstract: An optical device for fluorescence imaging equipped with a plurality of optical elements, wherein a silicone-based bonding agent containing a low-autofluorescent substance is interposed between the optical elements to bond the plurality of optical elements to each other.

Abstract: A fluorescence observing apparatus has an illumination system for irradiating a specimen with exciting light and an observation system for observing fluorescent light emanating from the specimen. Low-fluorescence glass is used for lenses of the first and seventh lens units of an objective lens used in both the illumination system and the observation system. The low-fluorescence glass has a platinum content of less than 1 ppm. Whereby, high-precision and high-quality fluorescence observations and fluorescence measurements become possible.

Abstract: In a connector including a contact and a housing holding the contact, a shell is coupled with the housing. The housing has a coupling portion to be coupled with a mating connector in a first direction. The contact has a contacting portion disposed in the coupling portion. The shell includes an opening edge defining an opening faced to the coupling portion and a guide portion disposed in the coupling portion to guide movement of the mating connector in the first direction.

Abstract: An infrared absorption filter consisting of 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide than CuO or CdO is provided. A process of fabricating an infrared absorption filter is also provided. The process comprises introducing a divalent copper compound and a compound of a metal species acting as a network modifier oxide in the form of metal ions into a wet gel. The wet gel can be dipped in a dipping solution to precipitate the divalent copper compound and the compound of a metal species acting as the network modifier oxide in the wet gel. The wet gel can be dried and heated, thereby obtaining an infrared absorption glass. The infrared absorption glass can be cut and polished, thereby fabricating a filter.

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: In a method of removing an aromatic halide from oil containing the aromatic halide, the aromatic halide compound being extracted from the oil containing the aromatic halide compound safely and highly efficiently, by extraction using an extracting solvent containing 1,3-dialkyl-2-imidazolidinone which is sulfur free and has extremely high extraction separation ability, or by using an extraction solvent containing an aqueous solution of 1,3-dialkyl-2-imidazolidinone. A system of removing aromatic halide compound from oil containing the aromatic halide compound includes a first supply source of a first extracting solvent containing 1,3-dialkyl-2-imidazolidinone; a second supply source of the oil containing the aromatic halide compound; and a first extractor which extracts the aromatic halide compound from the oil containing the aromatic halide compound supplied from the second supply source, by the first extracting-solvent supplied from the first supply source.

Abstract: An infrared absorption filter consisting of 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide than CuO or CdO is provided. A process of fabricating an infrared absorption filter is also provided. The process comprises introducing a divalent copper compound and a compound of a metal species acting as a network modifier oxide in the form of metal ions into a wet gel. The wet gel can be dipped in a dipping solution to precipitate the divalent copper compound and the compound of a metal species acting as the network modifier oxide in the wet gel. The wet gel can be dried and heated, thereby obtaining an infrared absorption glass. The infrared absorption glass can be cut and polished, thereby fabricating a filter.

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.