Abstract: The FIFO device includes an MCF, a first lens having a first optical axis parallel to a center axis of the MCF, a group of second lenses including the same number of second lenses having a second optical axis parallel to the first optical axis as cores of the MCF, and a group of single-core optical fibers including the same number of single-core optical fibers as the second lenses. An end face of each single-core optical fiber is obliquely polished so as to incline in a predetermined inclination direction with respect to a plane orthogonal to the center axis by a predetermined polishing angle. Oblique polishing directions of surrounding single-core optical fibers are set so that the corresponding second lenses are positioned closer to the first optical axis or to the first lens compared to their positions at the time when the surrounding single-core optical fibers are not obliquely polished.

Abstract: An optical filter device includes: a first multi-core optical fiber including a plurality of first cores; a first lens; an optical filter which is rotated by a rotation angle about a rotation axis; a second lens; and an optical fiber including cores which the emission light beams from the second lens enter. When directions directed from a reference axis toward one side and another side with respect to the reference axis along an orthogonal axis orthogonal to an optical axis and the reference axis are defined as first and second orthogonal directions, respectively, a circumferential orientation of the first multi-core optical fiber is set so that a separation distance is minimized. The separation distance is a sum of distances from the reference axis to first cores that are most separated away from the reference axis in the first and second orthogonal directions, respectively.

Abstract: A preform for optical fiber made of a quartz glass sintered body which is made from quartz glass powder as a main raw material, in which at least a portion of the quartz glass sintered body is an opaque body, the opaque body has a visible light transmittance of 90% or less at a length of 5 mm or less in one direction, and the opaque body has a bulk density of 2.1 g/cm3 or more, or the opaque body has a visible light transmittance of 90% or less at a length of 5 mm or less in one direction, and the opaque body has an open porosity of 3.5% or less.

Abstract: Provided is an optical module comprising a substrate, a holder, and a spacer. An optical waveguide is formed in/on the substrate and end parts thereof are protruding from one surface of the substrate. The holder holds an optical fiber and exposes one end part of the optical fiber in such a manner that the one end part of the optical fiber can be optically connected to the end parts of the optical waveguide at a side of one surface of the holder. The spacer is held the one surface of the substrate and the one surface of the holder.

Abstract: Provided is an optical module comprising a substrate, a holder, and a spacer. An optical waveguide is formed in/on the substrate and end parts thereof are protruding from one surface of the substrate. The holder holds an optical fiber and exposes one end part of the optical fiber in such a manner that the one end part of the optical fiber can be optically connected to the end parts of the optical waveguide at a side of one surface of the holder. The spacer is held the one surface of the substrate and the one surface of the holder.

Abstract: An optical multiplexer/demultiplexer includes: first to n-th demultiplexed light input/output portions; a multiplexed light input/output portion; second to n-th interference film filters; and first to n?1-th mirrors. The first to n-th demultiplexed light input/output portions are disposed on a single plane and correspond to light having a single wavelength. The second to n-th interference film filters are disposed in front of the second to n-th demultiplexed light input/output portions. The first to n?1-th mirrors are disposed in front of the first demultiplexed light input/output portion and in front of the n?1-th interference film filters. Light from the first demultiplexed light input/output portion strikes the first to n?1-th mirrors and the second to n-th interference film filters and is input to the multiplexed light input/output portion. Light output from the multiplexed light input/output portion strikes the second to n-th interference film filters and first to n?1-th mirrors.

Abstract: An optical multiplexer/demultiplexer includes: first to n-th demultiplexed light input/output portions; a multiplexed light input/output portion; second to n-th interference film filters; and first to n?1-th mirrors. The first to n-th demultiplexed light input/output portions are disposed on a single plane and correspond to light having a single wavelength. The second to n-th interference film filters are disposed in front of the second to n-th demultiplexed light input/output portions. The first to n?1-th mirrors are disposed in front of the first demultiplexed light input/output portion and in front of the n?1-th interference film filters. Light from the first demultiplexed light input/output portion strikes the first to n?1-th mirrors and the second to n-th interference film filters and is input to the multiplexed light input/output portion. Light output from the multiplexed light input/output portion strikes the second to n-th interference film filters and first to n?1-th mirrors.

Abstract: This steel material for bearings includes prescribed components in the steel, the oxide inclusions in the steel that have a minor axis of 1 ?m or greater satisfying the following conditions (1) and (2). (1) The average composition contains specific respective amounts of CaO, Al2O3, SiO2, and TiO2, and CaO+Al2O3+SiO2+TiO2?60%. (2) The proportion of oxide inclusions in which TiN occurs at the interface of the oxide inclusions and the steel is 30% or more of the total of the oxide inclusions.

Abstract: Apparatus for supplying diluted gaseous fuel to not more than a lower limit combustion concentration at downstream of suction type sintering machine including a hood having similar width as a circularly-moving pallet and arranged above charged layer to surround the pallet in all directions, pipes disposed at upper position of charged layer in the hood and supplying the fuel air inside the hood, baffle plates formed by arranging plate materials having dog-leg shaped cross-section in plural rows and steps at intervals in the widthwise and height directions, respectively, of the hood to make each interval formed between adjacent plate materials in widthwise direction of the hood in each steps vertically alternate; fences having a void and arranged on both sides upper ends of the hood; vortex suppressing plates formed between fences at intervals having a void ratio, 20˜80%; whereby the gaseous fuel leakage supplied to the outside is prevented.

Abstract: Apparatus for supplying diluted gaseous fuel to not more than a lower limit combustion concentration at downstream of suction type sintering machine including a hood having similar width as a circularly-moving pallet and arranged above charged layer to surround the pallet in all directions, pipes disposed at upper position of charged layer in the hood and supplying the fuel air inside the hood, baffle plates formed by arranging plate materials having dog-leg shaped cross-section in plural rows and steps at intervals in the widthwise and height directions, respectively, of the hood to make each interval formed between adjacent plate materials in widthwise direction of the hood in each steps vertically alternate; fences having a void and arranged on both sides upper ends of the hood; vortex suppressing plates formed between fences at intervals having a void ratio, 20˜80%; whereby the gaseous fuel leakage supplied to the outside is prevented.

Abstract: A magneto-optical device is provided with a non-magnetic substrate, a magneto-optical crystal embedded in recessed portions formed in the surface of the non-magnetic substrate at positions where pixels are to be located, and a partitioning wall monolithic with the non-magnetic substrate and magnetically separating the magneto-optical crystal from each other at the position of a gap between the pixels, wherein the entire surface of the magneto-optical device is flattened.

Abstract: Magneto-optical crystals of each pixel of a magneto-optical device are magnetically and completely separated, and the entire surface thereof is flattened. Disclosed is a magneto-optical device including a non-magnetic substrate, a magneto-optical crystal embedded in recessed portions formed in the surface of the non-magnetic substrate at positions where pixels are to be located, and a partitioning wall monolithic with the non-magnetic substrate and magnetically separating the magneto-optical crystal from each other at the position of a gap between the pixels, wherein the entire surface of the magneto-optical device is flattened.

Abstract: A method and an apparatus for producing hydrogen and a hydrogen production plant are provided. In the method, hydrogen production requiring high temperature is performed at low cost using energy of relatively low-temperature exhaust heat discharged form various types of heat processes, and the apparatus can readily start and suspend operation and whose running cost and equipment cost are reduced. These are achieved by a method for producing hydrogen and a hydrogen production apparatus and plant for realizing the method.

Abstract: A smelting reduction method comprising (a) charging a carbonaceous material and an ore into a reacting furnace to directly contact the carbonaceous material and the ore; (b) reducing the ore until at least a part of the ore is metallized, the resultant reduced ore containing at least a part of metallized metal being produced; (c) charging the carbonaceous material and the ore containing at least a part of the metallized metal from step (b) into a smelting furnace having a metal bath; and (d) blowing a gas containing 20% or more of oxygen into the metal bath in the smelting furnace to produce molten iron.

Abstract: The invention provides a method for manufacturing molten metal at low cost and high productivity by melt-reducing a metal oxide and/or a metal hydroxide such as iron ore. To do this, at least the metal oxide and/or the metal hydroxide such as iron ore is preliminarily mixed, preliminarily mixed and granulated, or preliminarily mixed and molded with a carbonaceous material to prepare a mixture of raw materials. The mixture of raw materials is preliminarily reduced in a prereduction furnace of rotary hearth type, rotary kiln type, or the like to average metallization degree of the metal oxide and/or the metal hydroxide from 5 to 55%, which is then charged to a melting furnace for metal smelting, where the mixture of the raw materials is melted and finally reduced using the carbonaceous material as the reducing agent and using the combustion heat of the carbonaceous material and of carbon monoxide generated in the furnace as the major heat source.

Abstract: The refining method of low carbon molten iron comprises the steps of supplying the de-sulfurizing agent into the molten iron and agitating it so as to carry out the de-sulfurization, heating or carburizing the molten iron before or after the de-sulfurizing step, and de-carburizing the de-sulfurized metal in the decarburization treating furnace. The molten iron is produced by charging ores reduced until being metallized in the smelting reduction furnace. As the carbonaceous materials, powder coke, oil coke or waste plastic are used. As the iron source, the sintered ores of small grain size are used.

Abstract: The invention provides an apparatus for smelting reduction of iron ore which contains (1) at least one preheat and prereduction furnace which preheats and prereduces iron ore to a prereduction degree of less than 30%; (2) a smelting reduction furnace into which the preheated and prereduced iron ore, carbonaceous material and flux are charged and in which the preheated and prereduced iron ore is reduced; and (3) a top blow oxygen lance having first nozzles for decarburization and second nozzles for post-combustion, oxygen gas being blown through the first nozzles and the second nozzles into the smelting reduction furnace. At least one side tuyere is placed in a side wall of the smelting reduction furnace and at least one bottom tuyere is placed in a bottom wall of the smelting reduction furnace for blowing a stirring gas through the at least one side tuyere and the at least one bottom tuyere into the smelting reduction furnace.

Abstract: An apparatus for a smelting reduction of iron ore comprising a preheat and prereduction furnace which preheats and prereduces iron ore, a smelting reduction furance into which said preheated and prereduced iron ore, carbonaceous material and fluxes are charged and in which said preheated and prereduced iron ore are smelted and reduced, a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles and blowing oxygen into said smelting reduction furance, and at least one side tuyere placed at a side wall of the smelting reduction furnace and at least one bottom tuyere placed at a bottom of the smelting reduction furnace through which a stirring gas is respectively blown so that at least a part of said stirring gas introduced through said at least one side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through said at least one bottom tuyere.