Abstract: A method and an apparatus for aligning a diffraction grating align the longitudinal direction of grooves of a diffraction grating to a predetermined direction. The method and apparatus detect a diffracted light pattern sent from the diffraction grating, and displace the diffraction grating such that the direction of an arranging direction obtained from the diffracted light pattern is aligned in the predetermined direction.

Abstract: The invention provides a multilayer-coated substrate which has recesses and projections of an accurate shape on the surface and has high heat resistance and a high degree of integration, and further provides a process for producing the same.

Abstract: A diffraction optical element including an element body having a large number of grooves formed on its surface to form a grating, and a grating shape adjusting layer deposited on a grating surface of the element body by oblique incidence or material particles onto the grating surface, wherein the grating shape adjusting layer per se is made of a reflecting film material By the grating shape adjusting layer, the contour shape of the resulting grating surface in a section perpendicular to a lengthwise direction of the grooves is made not similar to the sectional shape of the element body. A reflecting film may be formed on a grating shape adjusting layer made of another material. A reflecting film may be provided on the element body before a grating shape adjusting layer made of a transparent dielectric material is provided on the reflecting film.

Abstract: As a feature of a glass substrate having at least one fine hole according to the invention, a side wall surface of the fine hole is connected to each surface of the glass substrate by a curved surface as a boundary portion between the two. As another feature of the glass substrate, a layer denatured by machining is removed from the inner wall surface of the fine hole and the boundary portion between the wall surface and each surface of the glass substrate. The fine hole is produced by: forming a fine hole in a glass substrate by machining or laser machining; and then applying liquid-phase chemical etching to surfaces of the glass substrate and the fine hole. On this occasion, it is desirable that the etching liquid used for the liquid-phase chemical etching is either of an aqueous solution of hydrofluoric acid and an aqueous mixture solution of hydrofluoric acid and ammonium fluoride.

Abstract: A molding die having satisfactory releasability, a sol-gel composition produced using the molding die, and a process for producing a sol-gel composition. The molding die which is to be pressed against a sol-gel material for producing a sol-gel composition has a release film, e.g., a thin gold (Au) film, formed on the molding surface of the molding die through a buffer layer made of metals and/or inorganic oxides.

Abstract: A molding die having satisfactory releasability, a sol-gel composition produced using the molding die, and a process for producing a sol-gel composition. The molding die which is to be pressed against a sol-gel material for producing a sol-gel composition has a release film, e.g., a thin gold (Au) film, formed on the molding surface of the molding die through a buffer layer made of metals and/or inorganic oxides.

Abstract: A molding die having satisfactory releasability, a sol-gel composition produced using the molding die, and a process for producing a sol-gel composition. The molding die which is to be pressed against a sol-gel material for producing a sol-gel composition has a release film, e.g., a thin gold (Au) film, formed on the molding surface of the molding die through a buffer layer made of metals and/or inorganic oxides.

Abstract: According to the present invention, there is provided a mold constituted by an electrically conductive thin plate having a predetermined surface shape, and an electrically insulating reinforcement material, wherein the electrically conductive thin plate and the electrically insulating reinforcement material are bonded to each other by an anodic bonding method. Particularly, the electrically conductive thin plate is preferably formed out of silicon single crystalline and the electrically insulating reinforcement material is preferably oxide glass.

Abstract: A reflection type diffraction grating according to the present invention has a structure in which a metal film as a first layer with reflectance not lower than 30% with respect to the wavelength of incident light and a transparent dielectric film as a second layer are laminated successively on the surface of the reflection type diffraction grating. With respect to the wavelength of incident light, the metal film has a refractive index selected to be not higher than 1.5 and an extinction coefficient selected to be not smaller than 6.0. The transparent dielectric film has a refractive index selected to be in a range of from 1.30 to 1.46, both inclusively, with respect to the wavelength of incident light and has an optical film thickness selected to be in a range of from 0.20&lgr; to 0.38&lgr;, both inclusively, when &lgr;is the wavelength of incident light.