Abstract: A discrimination filtering device includes a filter and a filter having different pass bands, a detection unit, a processing unit, and a result output unit. The detection unit detects an electromagnetic wave from an object that is the target of identification through the filters. The pass band of the filters is designed to be suitable for object discrimination. The processing unit substitutes the output from the detection unit into a discrimination function determined based on the pass band of the filters and the teaching spectrum obtained in advance to infer the group which the object belongs to based on the substituted result.

Abstract: A discrimination filtering device includes a filter and a filter having different pass bands, a detection unit, a processing unit, and a result output unit. The detection unit detects an electromagnetic wave from an object that is the target of identification through the filters. The pass band of the filters is designed to be suitable for object discrimination. The processing unit substitutes the output from the detection unit into a discrimination function determined based on the pass band of the filters and the teaching spectrum obtained in advance to infer the group which the object belongs to based on the substituted result.

Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.

Abstract: An optical fiber has a core region and a cladding region surrounding the core region. The core region and the cladding region are made of a base material containing silica glass as a principal component. A plurality of holes extending along an axial direction are arranged at least in the cladding region. In the optical fiber, the base material has a hydroxyl mole fraction of not less than 10 ppm, or a fluorine content of not less than 0.2% by weight.

Abstract: An optical fiber has a core region and a cladding region surrounding the core region. The core region and the cladding region are made of a base material containing silica glass as a principal component. A plurality of holes extending along an axial direction are arranged at least in the cladding region. In the optical fiber, the base material has a hydroxyl mole fraction of not less than 10 ppm, or a fluorine content of not less than 0.2% by weight.

Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.

Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.

Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.

Abstract: An apparatus and method for sterilizing a root canal in which the apparatus contains an light source for generating bactericidal ultraviolet rays and an optical fiber coupled to the light source for transmitting the ultraviolet rays to and emitting the rays from an emitting end of the optical fiber placed in the root canal. Also included in a fiber protecting pipe that both protects the fiber and allows the fiber to be easily guided into the root canal. A flexible tube disposed over the emitting end of the root canal protects the exposed end of the optical fiber. Also, an arrangement of two optical fibers allows various shaped fiber protecting pipes to be used and a hand held coupling device couples two optical fibers.

Abstract: At the end of an optical fiber bundle, a reflecting member is provided to deflect the emitted light from a portion of the fibers in a direction transverse to the axis of the fiber bundle, thereby enhancing the ability of the fiber bundle to irradiate lateral surfaces while the undeflected light maintains the irradiation of a surface confronting the axial end face of the fiber bundle.