Abstract: The present invention is a method for producing a single crystal with pulling the single crystal from a raw material melt in a chamber by CZ method, wherein when growing the single crystal, where a pulling rate is defined as V and a temperature gradient of the crystal is defined as G during growing the single crystal, the temperature gradient G of the crystal is controlled by changing at least two or more of pulling conditions including a diameter of the straight body of the single crystal, a rotation rate of the single crystal during pulling the single crystal, a flow rate of an inert-gas introduced into the chamber, a position of a heater heating the raw material melt and a distance between the melt surface of the raw material melt and a heat insulating member provided in the chamber so as to oppose to the surface of the raw material melt, thereby V/G which is a ratio of the pulling rate V and the temperature gradient G of the crystal is controlled so that a single crystal including a desired defect region

Abstract: A rolling bearing intended for longer life by improving seizure resistance and wear resistance in the circumstance with slip contact or in the circumstance where lubricant tends to be exhausted, which is manufactured by applying carburization or carbonitridation to an Si-added material to disperse and precipitate carbides or carbonitrides containing Si or Si—X (X=one or more of Mn, Mo, and Cr) thereby improving the seizure resistance and the wear resistance by the self-lubrication effect thereof, the size of the carbides or carbonitrides being preferably 10 ?m or less for preventing flaking, and the area ratio for the carbides or carbonitrides being preferably 1.0–30% for obtaining sufficient self-lubrication effect.

Abstract: In a method for producing an SOI wafer comprising steps of implanting ions from a bond wafer surface to form an ion-implanted layer inside the wafer, bonding the ion-implanted bond wafer surface and a surface of a base wafer via an oxide film or directly, and forming an SOI wafer by delaminating by heat treatment a part of the bond wafer at the ion-implanted layer, the bond wafer is a silicon wafer that consists of a silicon single crystal grown by Czochralski method, that is occupied by N region outside OSF generated in a ring shape and that has no defect region detected by Cu deposition method. Thereby, even an extremely thin SOI layer having a thickness of 200 nm or less, can provide an SOI wafer that has an excellent electric property without micro pits caused by acid cleaning, and can be produced without increasing the number of processes.

Abstract: A wavelength selective optical switch according to the present invention detects wavelengths of signal lights input to a signal light input port in a main body portion which performs the switching of optical paths for each wavelength by an angular control of a plurality of mirrors, and also, monitors the intensity of a monitor light which is generated in an internal light source and is given from a monitor light input port disposed in the main body portion to be led to a monitor light output port, to feedback control a reflecting surface angle of the mirror corresponding to the wavelength of the signal light which is not input to the signal light input port, so that the output intensity of the monitor light becomes maximum. As a result, it is possible to reliably control the reflective surface angle of the mirror corresponding to the wavelength of the signal light which is not input, and therefore, the crosstalk doe not occur even when the signal light is newly input.

Abstract: The present invention is a method for producing a single crystal of which a whole plane in a radial direction is a defect-free region with pulling the single crystal from a raw material melt in a chamber by Czochralski method, wherein a pulling condition is changed in a direction of the crystal growth axis during pulling the single crystal so that a margin of a pulling rate is always a predetermined value or more that the single crystal of which the whole plane in a radial direction is a defect-free region can be pulled. Thereby, there can be provided a method for producing a single crystal in which when a single crystal is produced by CZ method, the single crystal of which a whole plane in a radial direction is a defect-free region entirely in a direction of the crystal growth axis can be produced with stability.

Abstract: An object of the invention is to provide a mirror fixing method capable of reducing stress distortion of a surface of a mirror which constitutes an optical system, with hardly deforming a surface shape of the mirror. To this end, the present mirror fixing method is characterized in that a mirror part including a base plate formed with a mirror on one face thereof, is provided with a boss on the other face of the base plate opposite to the face on which the mirror is formed, and only the boss is fixed, so that the mirror part excluding the boss is not in contact with other members.

Abstract: An SOI wafer in which a base wafer and a bond wafer respectively consisting of silicon single crystal are bonded via an oxide film, and then the bond wafer is thinned to form a silicon active layer, wherein the base wafer is formed of silicon single crystal grown by Czochralski method, and the whole surface of the base wafer is within N region outside OSF region and doesn't include a defect region detected by Cu deposition method, or the whole surface of the base wafer is within a region outside OSF region, doesn't include a defect region detected by Cu deposition method, and includes I region containing dislocation cluster due to interstitial silicon. Thereby, there is provided an SOI wafer that retains high insulating properties and has an excellent electrical reliability in device fabrication even in the case of forming an extremely thin interlevel dielectric oxide film with, for example, a thickness of 100 nm or less.

Abstract: A rolling bearing for belt-type continuously variable transmission with a metal belt including pieces has an inner ring; an outer ring; and rolling elements, wherein at least one of the inner ring, the outer ring and the rolling element is made of an iron alloy having a chromium content of from 2.5 to 20.0% by weight.

Abstract: In a wavelength selecting optical switch, a shutter is situated near an incident position, which is a position at which the light falls onto the mirrors, and has a plurality of blocking members that prevent or allow light to be incident onto respective mirrors. Moreover, a control unit controls a blocking member corresponding to a mirror of which an angle is to be changed so that the blocking member prevents the light to be incident onto the corresponding mirror.

Abstract: An object of the invention is to easily realize an optical element using an etalon type structure, capable of changing a periodic transmission wavelength characteristic in an axial direction of transmissivity, and also capable of changing a periodic characteristic with respect to wavelength. To this end, a transmission wavelength characteristics variable optical element according to the invention comprises: a light interference section including a pair of wedge shape magneto-optic crystals arranged with taper faces thereof in close contact, that can change a distance between reflecting films formed on parallel planes of the magneto-optic crystals, by relatively moving the magneto-optic crystals by movable sections, permanent magnets for applying a fixed magnet field to the pair of magneto-optic crystals, an electromagnet for applying a variable magnetic field in a direction different to the fixed magnetic field, and a variable current source controlling the current flowing into the electromagnet.

Abstract: In a method for producing a silicon single crystal by Czochralski method, the single crystal is grown with controlling a growth rate between a growth rate at a boundary where a defect region detected by Cu deposition remaining after disappearance of OSF ring disappears when gradually decreasing a growth rate of silicon single crystal during pulling and a growth rate at a boundary where a high oxygen precipitation Nv region having a density of BMDs of 1×107 numbers/cm3 or more and/or a wafer lifetime of 30 ?sec or less after oxygen precipitation treatment disappears when gradually decreasing the growth rate further. Thereby, there is provided a silicon single crystal which does not belong to any of V region rich in vacancy, OSF region and I region rich in interstitial silicon, and has excellent electrical characteristics and gettering capability, so that yield of devices can be surely improved, and also an epitaxial wafer.

Abstract: A wavelength dispersion compensating apparatus of the invention comprises: a VIPA plate capable to output incident lights at different angles according to wavelengths; a variable dispersion diffraction grating which can angularly disperse the lights of respective wavelengths output from the VIPA plate, in a direction substantially perpendicular to a direction of angular dispersion in the VIPA plate and also capable to change an amount of the angular dispersion; a light return apparatus which condenses the output lights from the variable dispersion diffraction grating and reflects them by a mirror, to return them to the VIPA plate side; and a stage rotation mechanism which rotates a movable stage on which the lens and the mirror are mounted, according to a diffraction angle in the variable dispersion diffraction grating, so as to enable wavelength dispersion and wavelength dispersion slope to be given to a WDM light, to be changed independently.

Abstract: A wavelength dispersion compensating apparatus of the invention comprises: a VIPA plate capable to output incident lights at different angles according to wavelengths; a variable dispersion diffraction grating which can angularly disperse the lights of respective wavelengths output from the VIPA plate, in a direction substantially perpendicular to a direction of angular dispersion in the VIPA plate and also capable to change an amount of the angular dispersion; a light return apparatus which condenses the output lights from the variable dispersion diffraction grating and reflects them by a mirror, to return them to the VIPA plate side; and a stage rotation mechanism which rotates a movable stage on which the lens and the mirror are mounted, according to a diffraction angle in the variable dispersion diffraction grating, so as to enable wavelength dispersion and wavelength dispersion slope to be given to a WDM light, to be changed independently.

Abstract: The centerline average roughness of the raceway surface of at least the fixed ring of bearing rings is controlled to be 0.025 to 0.075 ?mRa, thereby suppressing the rotation slip of the rolling elements so as to prevent flaking that is accompanied by a structural change. This enables prolongation of the life of bearings. At least the fixed ring of the bearing rings contains, as alloy ingredients at a ratio of from 0.50 to 1.20% by mass of carbon, from 0.10 to 1.50% by mass of silicon, from 0.1 to 2.0% by mass of manganese, from 3.0 to 6.0% by mass of chromium, 2.0% by mass or less of molybdenum, and 1.0% by mass or less of vanadium, whereby the necessary hardness is obtained and the structure is stabilized. This enables prolongation of the life of bearings.

Abstract: An optical device includes a small and low-cost variable polarization plane rotator that can control a rotation angle of the polarization plane easily. A variable polarization plane rotator is provided with a ?/4 phase plate having an optical axis in the same direction as, or at a 90 degree angle relative to, a polarization direction of an input light beam. A phase difference variable element has an optical axis at a ±45 degree angle relative to the optical axis of the ?/4 phase plate, to apply a variable phase difference between the polarization components parallel to and perpendicular to the optical axis thereof. A phase difference adjustment section adjusts the variable phase difference of the phase difference variable element, wherein the input light beam after being transmitted through the phase difference variable element to form elliptically polarized light or circularly polarized light, is transmitted through the ?/4 phase plate to form linearly polarized light.

Abstract: A rolling bearing has the radius of curvature of the raceway on an inner ring and an outer ring is from not smaller than 50.1% to not greater than 51.9% of the diameter of the balls, and at least one of the compositions of the bearing is obtained by forming an alloy steel having a carbon (C) content of from not smaller than 0.50% to not greater than 0.90%, a chromium (Cr) content of from not smaller than 3.0% to not greater than 15.0%, a manganese (Mn) content of from not smaller than 0.10% to not greater than 2.0%, a silicon (Si) content of from not smaller than 0.10% to not greater than 2.0%, a molybdenum (Mo) content of zero or not greater than 2.0% by weight, and a vanadium (V) content of zero or not greater than 2.0%, by weight.

Abstract: The present invention is a method of manufacturing a silicon single crystal by Czochralski method without performing Dash Necking method, wherein a temperature variation at a surface of a silicon melt is kept at ±5° C. or less at least for a period from a point of bringing the tip end of a seed crystal into contact with the silicon melt to a point of shifting to pull the single crystal.

Abstract: Light input from a single-mode fiber is collected into linear light beams by a line focuser, and collected on a VIPA element. A light beam output from the VIPA element is made to pass through a space filter having a predetermined transmission loss characteristic, and focused on a mirror with a focusing lens. The light is reflected by the mirror, again passes through the space filter via the focusing lens, enters the VIPA element, and again enters the single-mode fiber via the line focuser. The insertion loss wavelength characteristic of the wavelength dispersion compensator using the VIPA element is optimized by being superimposed on the transmission loss characteristic of the space filter.

Abstract: A VIPA plate having a configuration where a translucent reflection film and a total reflection film are respectively arranged on one side and the other side of a transparent parallel plate can be used as a wavelength dispersion compensator by using a special mirror and a lens. However, the transparency characteristic of the wavelength dispersion compensator using such a VIPA plate is a periodical characteristic which is asymmetric with a central wavelength in a wavelength regime. Accordingly, not parallel light but converged or diverged light having angular dispersion is input to an etalon plate, so that a filter whose transparency characteristic is an asymmetric periodical characteristic which is reverse to the VIPA plate is configured for the central wavelength in the wavelength regime. With this filter, the transparency characteristic of the wavelength dispersion compensator using the VIPA plate is optimized.

Abstract: A cabinet provided with light input/output holes accommodates a VIPA optical element, a lens, a fixing material fixing the VIPA optical element. A temperature-controlled heater controls the temperature of and inside the cabinet. Both the light input and output holes of the cabinet are blocked by the fixing material and the lens, respectively, so that temperature inside the cabinet is not influenced by the outside air.