Abstract: A glass for laser processing that is processed through laser beam irradiation, wherein the glass for laser processing has a composition that satisfies the following relationships: 40?M[NFO]?70; 5?(M[TiO2])?45; and 5?M[NMO]?40, where M[NFO], M[TiO2], and M[NMO] denote the content by percentage of network forming oxides (mol %), that of TiO2 (mol %), and that of network modifying oxides (mol %), respectively. With this structure, a glass for laser processing is obtained in which not only the vicinity of the surface thereof but also the inner portion thereof can be laser-processed.

Abstract: A waveguide element 21 including a photonic crystal waveguide including a core 4 that is constituted by a photonic crystal having a refractive index periodicity at least in one direction, and that propagates an electromagnetic wave in a direction in which the photonic crystal does not have the refractive index periodicity. At least one of materials forming the core 4 constituted by the photonic crystal, and at least a portion of a cladding in contact with a side face of the core 4 are constituted by a fluid 6. Thus, it is possible to provide a waveguide element that can be used as a light control element, can be produced easily and also can be applied to an optical sensor.

Abstract: A transmissive diffraction grating includes a substrate and a plurality of ridges provided in a mutually parallel manner at constant periodicity p on the substrate. The ridges include a first layer, a second layer (refractive index n2: 2.0-2.5), and a third layer with non-continuous refractive indices, arranged in that order from the substrate outward. The first layer adjacent the substrate, in terms of its refractive index, exhibits a difference of 0.1 or less relative to the substrate. The second layer has a higher refractive index than the first layer and third layer and satisfies the following conditions. For a single ridge, the cross-sectional area S of a cross-section of the second layer perpendicular to the longitudinal direction of said ridge is in the range of 0.75p2k1?2/(n2?1)<S<1.20p2k1?2/(n2?1), were, ? is the angle of incidence onto the diffraction grating face, expressed in radian units, and the constant k1 is 1.1. The thickness d2 of the second layer is in the range of 0.

Abstract: A surface of a substrate is coated with a sol solution containing metal alkoxide. A gelled material of the sol solution is pressed against a molding tool while the gelled material is kept soft. Thus, the gelled material is molded. Then, the gelled material is hardened. As a result, protrusions of the hardened gel layer 14 are formed on the substrate so that an irregular texture substrate is formed. A multilayer thin film constituted by a plurality of layers of at least two kinds of materials with different refractive indexes is laminated on a surface of the irregular texture substrate.

Abstract: A transmission type polarizing element 1 includes a dielectric substrate 3 having a structure in which a plurality of ridges 2 with an angle section are arranged parallel to each other on one side of the dielectric substrate 3, a thin film 4 that is made of a light absorbing substance and formed on the surfaces of the plurality of ridges 2 with an angle section, and a first dielectric substance layer 5 covering the surface of the thin film 4 that faces away from the dielectric substrate 3. When light is incident perpendicularly on the dielectric substrate 3, this transmission type polarizing element 1 transmits a TM polarizing component of the incident light whose magnetic field vibrates in the same direction as the longitudinal direction of the ridges 2 and absorbs a TE polarizing component of the incident light whose electric field vibrates in the same direction as the longitudinal direction of the ridges 2.

Abstract: A glass substrate processing method includes irradiating laser light L onto a glass substrate 1 such that the laser light L is focused within the glass substrate 1, thereby forming a high density area 3 that has a higher density than areas where the laser light L is not irradiated around the portion where the laser light L is focused; and performing chemical etching on the glass substrate 1 using an etching solution such that at least a portion of the high density area is allowed to remain, thereby forming a projection 2 on a surface 1a of the glass substrate 1.

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: Titanium is added in the form of atoms, a colloid, or ions to a glass to be subjected to laser processing in which the ablation or vaporization caused by the energy of an absorbed laser light is utilized. Since titanium can be incorporated into the glass through melting, the threshold value for processing can be easily regulated by changing the amount titanium to be added and a material having evenness in processability can be obtained.

Abstract: An optical waveguide device 1a is configured to include a straight waveguide 2a and bottleneck portions 3a provided in two locations in the longitudinal direction of the waveguide 2a. In the optical waveguide device 1a, light confinement is implemented in all surfaces. This permits provision of an optical waveguide device, wherein a reflector or resonator can be provided in a waveguide using a simple configuration.

Abstract: A glass processing method comprising steps (i), (ii) carried out in the order mentioned. In step (i), a laser pulse (11) with a wavelength ? is condensed by a lens and is applied to a glass plate (12) to form an altered portion (13) at the portion, irradiated with a laser pulse (11), of the glass plate (12). In step (ii), the altered portion (13) is etched by using an etchant having an etching rate larger for the altered portion (13) than that for the glass plate (12). The laser beam used includes the following conditions: The pulse width of a laser pulse (11) ranges from ins to 200 ns, with a wavelength ? being up to 535 nm. The absorption coefficient of the glass plate (12) at a wavelength ? is up to 50 cm?1. A value obtained from a lens focal distance L (mm) divided by the beam diameter D (mm) of the laser pulse (11) when entering the lens is at least 7.

Abstract: A waveguide element 21 including a photonic crystal waveguide including a core 4 that is constituted by a photonic crystal having a refractive index periodicity at least in one direction, and that propagates an electromagnetic wave in a direction in which the photonic crystal does not have the refractive index periodicity. At least one of materials forming the core 4 constituted by the photonic crystal, and at least a portion of a cladding in contact with a side face of the core 4 are constituted by a fluid 6. Thus, it is possible to provide a waveguide element that can be used as a light control element, can be produced easily and also can be applied to an optical sensor.

Abstract: A processing method for glass substrate of the present invention includes: applying heat and external force to a glass substrate and then cooling it down to thereby form a compression stressed part having a different etching rate from that of other parts with respect to an etching reagent to be used, on the surface of the glass substrate and in the vicinity thereof; and performing chemical etching using the etching reagent on the glass substrate having the compression stressed part formed thereon, so as to form a relief on the surface of the glass substrate.

Abstract: A waveguide element using a photonic crystal having a refractive index periodicity in one direction is provided with an input portion causing propagation light due to a band on a Brillouin zone boundary within the photonic crystal.

Abstract: The present invention improves a method of forming a surface unevenness using a difference in etching rates, and relaxes limitations on substrates in this method. In a method of the present invention, an uneven surface is formed by a method including applying pressure to a predetermined region in a surface of a thin film formed on a substrate, and etching a region including at least a portion of the predetermined region and at least a portion of the reminder of the surface that excludes the predetermined region. An etching rate difference within the thin film increases freedom in selecting a substrate material.

Abstract: A glass for laser processing of the present invention can be laser-processed by causing ablation or evaporation by laser beam energy absorbed therein, wherein the glass for laser processing has a composition that satisfies the following conditions: 60?SiO2+B2O3?79 mol %; 5?Al2O3+TiO2?20 mol %; and 5?Li2O+Na2O+K2O+Rb2O+Cs2O+MgO+CaO+SrO+BaO?20 mol %, where 5?TiO2?20 mol %. The present invention can provide a glass for laser processing that has a low laser processing threshold value as well as a low thermal expansion coefficient.

Abstract: An optical waveguide device 1a is configured to include a straight waveguide 2a and bottleneck portions 3a provided in two locations in the longitudinal direction of the waveguide 2a. In the optical waveguide device 1a, light confinement is implemented in all surfaces. This permits provision of an optical waveguide device, wherein a reflector or resonator can be provided in a waveguide using a simple configuration.

Abstract: A processing method for glass substrate of the present invention includes: applying heat and external force to a glass substrate and then cooling it down to thereby form a compression stressed part having a different etching rate from that of other parts with respect to an etching reagent to be used, on the surface of the glass substrate and in the vicinity thereof, and performing chemical etching using the etching reagent on the glass substrate having the compression stressed part formed thereon, so as to form a relief on the surface of the glass substrate.

Abstract: A transmissive diffraction grating includes a substrate and a plurality of ridges provided in a mutually parallel manner at constant periodicity p on the substrate. The ridges include a first layer, a second layer (refractive index n2: 2.0-2.5), and a third layer with non-continuous refractive indices, arranged in that order from the substrate outward. The first layer adjacent the substrate, in terms of its refractive index, exhibits a difference of 0.1 or less relative to the substrate. The second layer has a higher refractive index than the first layer and third layer and satisfies the following conditions. For a single ridge, the cross-sectional area S of a cross-section of the second layer perpendicular to the longitudinal direction of said ridge is in the range of 0.75p2k1?2/(n2?1)<S<1.20p2k1?2/(n2?1), were, ? is the angle of incidence onto the diffraction grating face, expressed in radian units, and the constant k1 is 1.1. The thickness d2 of the second layer is in the range of 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 method for producing an aspherical structure according to the invention includes the steps of: forming a layer on a surface of a substrate so that the layer exhibits an etching rate distribution in a direction perpendicular to the surface of the substrate; forming a mask having a predetermined opening shape on the surface of the layer; and etching the layer to thereby form at least one aspherical concave portion. When each concave portion is used as a molding tool so that a resin with which the concave portion is filled is solidified and removed from the concave portions an aspherical lens array can be formed accurately.