Abstract: A glass substrate molding method includes: preparing a rotatable or wheelable molding die having a die surface and contacting the die surface with one of a pair of principal surfaces of a glass substrate made of a glass material containing an alkali metal oxide, the die having conductivity; keeping the one of principal surfaces contacted with the die surface at a temperature over 100° C. and equal to or lower than Tg+50° C.; applying direct-current voltage to the substrate to be higher voltage on the contacted one of principal surfaces than voltage on an opposite surface of the contacted one of principal surfaces; and rotating or wheeling the die and simultaneously moving the die or the substrate in a direction parallel to the contacted one of principal surfaces in conformity with rotation or wheeling speed of the die, to mold the contacted one of principal surfaces of the substrate.

Abstract: A glass substrate molding method includes: preparing a rotatable or wheelable molding die having a die surface and contacting the die surface with one of a pair of principal surfaces of a glass substrate made of a glass material containing an alkali metal oxide, the die having conductivity; keeping the one of principal surfaces contacted with the die surface at a temperature over 100° C. and equal to or lower than Tg+50° C.; applying direct-current voltage to the substrate to be higher voltage on the contacted one of principal surfaces than voltage on an opposite surface of the contacted one of principal surfaces; and rotating or wheeling the die and simultaneously moving the die or the substrate in a direction parallel to the contacted one of principal surfaces in conformity with rotation or wheeling speed of the die, to mold the contacted one of principal surfaces of the substrate.

Abstract: A method capable of forming a sufficiently thick low alkali concentration region without heating glass to a high temperature and even in an atmosphere which is not an atmosphere of plasma formation gas such as helium and argon, is provided. A glass substrate having a pair of main surfaces and being made of glass containing an alkali oxide in its composition, is disposed between a first electrode and a second electrode so that one main surface is separated from the first electrode and the other main surface is brought into contact with the second electrode, and a corona discharge is generated by applying a direct-current voltage to the first electrode as a positive electrode and the second electrode as a negative electrode, in a positive-electrode-side surface layer portion of the glass substrate, at least one positive ion including an alkali ion migrate toward the negative-electrode-side.

Abstract: A P2O5—BaO—ZnO—Nb2O5 type optical glass contains 25-50 wt. % P2O5, 15-35 wt. % BaO, 1-25 wt. ZnO, and 3-10 wt. % Nb2O5. The optical glass has a high refractive index (particularly preferably the refractive index nd of 1.6 or more), low dispersion (an Abbe number ?d of 42 or more), a low deformation point, and improved resistance to devitrification upon molding, and is suitable for precision-mold press molding or other molding processes and also suitable for transfer of a fine structure.

Abstract: An optical glass having a high refractive index (particularly preferably a refractive index of 1.6 or more), low dispersion (an Abbe number of 45 or more), a low deformation point, and improved resistance to devitrification upon molding, and suitable for precision-mold press molding or other molding processes and also suitable for transfer of a fine structure is provided. The optical glass contains 1.0-4.5 wt. % SiO2, 30.5-50.0 wt. % B2O3, 1.1-8.0 wt. % Li2O, 10.1-19.5 wt. % BaO, 15.5-30.0 wt. % ZnO, 3.0-15.0 wt. % Y2O3, and 10.0-19.5 wt. % La2O3.

Abstract: An optical glass having a high refractive index (particularly preferably a refractive index of 1.6 or more), low dispersion (an Abbe number of 45 or more), a low deformation point, and improved resistance to devitrification upon molding, and suitable for precision-mold press molding or other molding processes and also suitable for transfer of a fine structure is provided. The optical glass contains 1.0-4.5 wt. % SiO2, 30.5-50.0 wt. % B2O3, 1.1-8.0 wt. % Li2O, 10.1-19.5 wt. % BaO, 15.5-30.0 wt. % ZnO, 3.0-15.0 wt. % Y2O3, and 10.0-19.5 wt. % La2O3.

Abstract: A P2O5—BaO—ZnO—Nb2O5 type optical glass contains 25-50 wt. % P2O5, 15-35 wt. % BaO, 1-25 wt. ZnO, and 3-10 wt. % Nb2O5. The optical glass has a high refractive index (particularly preferably the refractive index nd of 1.6 or more), low dispersion (an Abbe number ?d of 42 or more), a low deformation point, and improved resistance to devitrification upon molding, and is suitable for precision-mold press molding or other molding processes and also suitable for transfer of a fine structure.

Abstract: A polarization split element 1 includes a substrate 2 and a plurality of ridge-shaped convex portions 3 provided in parallel with one another at equal intervals on the substrate 2, and performs polarization splitting with respect to light beams 4 incident to the plurality of the convex portions 3 by diffraction. This polarization split element 1 satisfies a conditional expression represented by: 1.6?n?2.2 and 0.6?P/??0.

Abstract: An optical element of the present invention includes a structure having at least one convex portion and at least one concave portion formed so as to be adjacent to either one of the convex portions. At least one surface of the structure is covered, and the optical element has a hollow portion. At least one surface of the structure is covered with a covering layer formed by a deposition process.

Abstract: A wavelength separator includes a one-dimensional photonic crystal structure formed by providing a plurality of grooves in parallel with one another at uniform intervals in a homogeneous medium, and has an incident end face formed obliquely with respect to a direction in which the grooves extend, and an output end face formed approximately perpendicular to the incident end face.

Abstract: A spectrometer using a diffraction grating includes a light-incident portion including an incident-side optical waveguide emitting a light beam that includes a plurality of wavelength components and that approximates a Gaussian beam, and a collimating lens that is arranged on an emission side of the incident-side optical waveguide and that converts the light beam approximating a Gaussian beam that is emitted from the incident-side optical waveguide into a substantially collimated light beam; a diffraction grating having grooves on its surface, on which the light beam that has been converted into the substantially collimated light beam by the collimating lens is incident, the diffraction grating spectrally separating the light beam by emitting light beams whose emission direction depends on their wavelength; and a light-emitting portion having a plurality of focusing lenses that respectively condense the light beams that have been spectrally separated by the diffraction grating.

Abstract: A spectrometer using a diffraction grating includes a light-incident portion including an incident-side optical waveguide emitting a light beam that includes a plurality of wavelength components and that approximates a Gaussian beam, and a collimating lens that is arranged on an emission side of the incident-side optical waveguide and that converts the light beam approximating a Gaussian beam that is emitted from the incident-side optical waveguide into a substantially collimated light beam; a diffraction grating having grooves on its surface, on which the light beam that has been converted into the substantially collimated light beam by the collimating lens is incident, the diffraction grating spectrally separating the light beam by emitting light beams whose emission direction depends on their wavelength; and a light-emitting portion having a plurality of focusing lenses that respectively condense the light beams that have been spectrally separated by the diffraction grating.

Abstract: In homogeneous materials, etching characteristics depend on properties inherent in these materials regardless of whether they are isotropic or anisotropic, and there have been limitations in realizing various desired shapes. A subject for the invention is to provide a gradient material which eliminates these limitations. A gradient material is provided in which the rate of etching with a specific chemical substance changes continuously or by steps from the outermost surface to an inner part thereof. This gradient material is made of a main material which contains an additive capable of changing the etching rate of the main material so that the concentration of the additive changes continuously or by steps. Especially when a glass material containing SiO2 as the main component is used as the main material and fluorine is used as the additive, then a gradient material in which the rate of etching with an aqueous solution of hydrofluoric acid changes in the depth direction can be obtained.

Abstract: A wavelength separator includes a one-dimensional photonic crystal structure formed by providing a plurality of grooves in parallel with one another at uniform intervals in a homogeneous medium, and has an incident end face formed obliquely with respect to a direction in which the grooves extend, and an output end face formed approximately perpendicular to the incident end face.

Abstract: An optical element of the present invention includes a structure having at least one convex portion and at least one concave portion formed so as to be adjacent to either one of the convex portions. At least one surface of the structure is covered, and the optical element has a hollow portion. At least one surface of the structure is covered with a covering layer formed by a deposition process.

Abstract: In homogeneous materials, etching characteristics depend on properties inherent in these materials regardless of whether they are isotropic or anisotropic, and there have been limitations in realizing various desired shapes. A subject for the invention is to provide a gradient material which eliminates these limitations. A gradient material is provided in which the rate of etching with a specific chemical substance changes continuously or by steps from the outermost surface to an inner part thereof. This gradient material is made of a main material which contains an additive capable of changing the etching rate of the main material so that the concentration of the additive changes continuously or by steps. Especially when a glass material containing SiO2 as the main component is used as the main material and fluorine is used as the additive, then a gradient material in which the rate of etching with an aqueous solution of hydrofluoric acid changes in the depth direction can be obtained.

Abstract: This invention provides a method of manufacturing a diffraction grating capable of scribing by an interference light at a lower power density than usual. That is, a coating solution containing a metal alkoxide and a &bgr;-diketone is coated on a substrate, the coated film is heat treated to form a gelled film and then an interference light is irradiated to the gelled film, to manufacture a diffraction grating.

Abstract: A film containing TiO2 and SiO2. It is formed by depositing TiO2 and SiO2 onto a substrate by sputtering method, or depositing their vapors thereon. The film is heat treated at a temperature of 200-1200° C. to form a film of anatase type TiO2 containing SiO2.

Abstract: An optical micro-machining method of glass characterized in that after light is applied to glass including SiO.sub.2 and 30-70 mol % GeO.sub.2, the irradiated area is removed by etching.

Abstract: A glass material variable in volume by irradiation with ultraviolet light has a GeO.sub.2 --SiO.sub.2 glass composition having a GeO.sub.2 content of 0.5 to 90 mol %, and is in the form of a thin film formed in an argon atmosphere or in an argon-oxygen mixed gas atmosphere by the high-frequency sputtering method.