Abstract: A mask with an opening pattern is placed on a substrate, and etching is carried out by use of anisotropy etching of crystal. The opening pattern of the mask is composed of broken lines, each of which is discontinued by discontinuing portions. By the etching, a birefringence optical element with a fine structure, in which trenches, each of which is discontinued by discontinuing portions, are juxtaposed periodically at a specified pitch, is obtained.

Abstract: A light-condensing head has a light source unit, a light-condensing element that condenses the light emitted from the light source unit, and an electrically conductive scatterer that, when irradiated with light, produces localized plasmon at the light condensation position of the light from the light-condensing element. The light emitted from the light source unit contains, at least in part thereof, polarized waves that constitute a rotation-symmetric radiating electric field vector distribution in which the electric field vectors have equal magnitudes at equal distances from the center of rotation symmetry. The electrically conductive scatterer has, in the light-receiving portion thereof that receives the light from the light-condensing element, rotation symmetry of order three or more.

Abstract: A two-dimensional photonic crystal surface-emitting laser having a photonic crystal (20) in which a photonic crystal periodic structure (21) is located in or near an active layer (first medium) (12) which emits light when carriers are injected thereto. The photonic crystal periodic structure (21) comprises a second medium with a refractive index different from that of the active layer scattered in two-dimensional periodic array. The photonic crystal periodic structure is of a square lattice structure or a triangular lattice structure which has translation symmetry but does not have rotation symmetry. Alternatively, the phtonic crystal periodic structure is of a square lattice structure or a rectangular lattice structure which is classified into pl, pm, pg or cm according to the two-dimensional pattern classification method. It is the most desirable that the lattice structure is composed of triangular lattice points.

Abstract: A diffraction grating device for splitting or coupling light beams permits the divergence of the light beams to be minimized easily. A first light beam is incident on a diffraction grating from the side thereof facing the inside of the device, and a second light beam is incident on the diffraction grating from the side thereof facing air. The diffraction grating transmits the first light beam by diffraction of the minus first order so that it travels in the reverse direction along the optical path of the second light beam before incidence, and transmits the second light beam by diffraction of the zero order. The second light beam, transmitted by diffraction of the zero order, spreads over a certain width of wavelengths, but does not diverge even after diffraction.

Abstract: An optical bidirectional module 10 having therein light emitting element 11 which transmits optical signal to the end facet of the optical fiber, light receiving element 12 which receives optical signal from the end facet of the optical fiber and stair-shaped multi-level grating 15, wherein the stair-shaped multi-level grating separates the first light path between the end facet of optical fiber and the light emitting element and the second light path between the end facet of optical fiber and the light receiving element by a different wavelength of each optical signal, when the module mixes and separates optical signal with different wavelengths traveling in opposite directions related to the end facet of the optical fiber 1, used for bidirectional optical fiber communication by means of a wavelength multiplex system.

Abstract: A diffraction grating device for splitting or coupling light beams permits the divergence of the light beams to be minimized easily. A first light beam is incident on a diffraction grating from the side thereof facing the inside of the device, and a second light beam is incident on the diffraction grating from the side thereof facing air. The diffraction grating transmits the first light beam by diffraction of the minus first order so that it travels in the reverse direction along the optical path of the second light beam before incidence, and transmits the second light beam by diffraction of the zero order. The second light beam, transmitted by diffraction of the zero order, spreads over a certain width of wavelengths, but does not diverge even after diffraction.

Abstract: A planar light emitting device 1 has a light emitting layer 5 that is formed on a glass substrate 2 and that emits light when a voltage is applied thereto or a current is injected thereinto and a two-dimensional diffraction grating 30 that has a first and a second medium 31 and 32 having different refractive indices and that has the second medium 32 arrayed two-dimensionally in the first medium 31. In the two-dimensional diffraction grating 30, the ratio of the area occupied by the second medium 32 to the sum of the area occupied by the first medium 31 and the area occupied by the second medium 32 is 25% or more but 60% or less.

Abstract: A mask with an opening pattern is placed on a substrate, and etching is carried out by use of anisotropy etching of crystal. The opening pattern of the mask is composed of broken lines, each of which is discontinued by discontinuing portions. By the etching, a birefringence optical element with a fine structure, in which trenches, each of which is discontinued by discontinuing portions, are juxtaposed periodically at a specified pitch, is obtained.

Abstract: An optical bidirectional module 10 having therein light emitting element 11 which transmits optical signal to the end facet of the optical fiber, light receiving element 12 which receives optical signal from the end facet of the optical fiber and stair-shaped multi-level grating 15, wherein the stair-shaped multi-level grating separates the first light path between the end facet of optical fiber and the light emitting element and the second light path between the end facet of optical fiber and the light receiving element by a different wavelength of each optical signal, when the module mixes and separates optical signal with different wavelengths traveling in opposite directions related to the end facet of the optical fiber 1, used for bidirectional optical fiber communication by means of a wavelength multiplex system.

Abstract: On a waveguide 34 formed on a substrate 33, a plurality of comblike shaped electrodes 37, 38 that generate surface acoustic waves 37a, 38a from different directions are provided. And a periodic refractive indices portion 40 is formed, where the refractive indices are periodically distributed in accordance with the wavelengths of the surface acoustic waves 37a, 38a generated by applying a voltage to the comblike shaped electrodes 37, 38. And by changing a frequency of the applying voltage for sequentially changing the wavelengths of the surface acoustic waves 37a, 38a, the exiting direction of the light exiting from the periodic refractive indices portion 40 is scanned. This makes it possible to provide an optical functional device and an optical scanning apparatus that perform light scanning less costly but at a high speed, and that can secure a wide scanning angle.

Abstract: Two-dimensional photonic crystal surface-emitting laser comprising a two-dimensional photonic crystal, having media different in refractive index arrayed in a two-dimensional cycle, disposed in the vicinity of an active layer that emits light by the injection of carriers, wherein the two-dimensional photonic crystal consists of square lattices having equal lattice constants in perpendicular directions, and a basic lattice consisting of a square with one medium as a vertex has an asymmetric refractive index distribution with respect to either one of the two diagonals of the basic lattice to thereby emit light in a constant polarizing direction.

Abstract: For balancing a wheel, which is formed of a rolled plate having varying thickness, the wheel is provided with a disk which is formed by a rolled plate having varying thickness in the rolling direction, wherein wheel balance is adjusted by radially adjusting the angle between the location of the thick part of the disk and the location of the air valve insertion hole, and the location of the air valve insertion hole certainly accords with the heaviest point by conforming the location of the air valve insertion hole with the location of the thick part of the disk.

Abstract: An optical module has a substrate, a waveguide, formed on the substrate, for guiding light, and a photonic crystal portion that has media having different refractive indices arranged in a periodic pattern and that is disposed in a channel of the waveguide on the substrate. Here, the photonic crystal and the substrate are integrally formed. The formation comprises the steps of forming an aluminum film on the top of a conductive substrate, forming a protective film on the aluminum film, removing the protective film from a predetermined area to form a window over the predetermined area, anodizing the aluminum film exposed through the window to form photonic crystals, removing the protective film, cladding the bottom of the substrate and forming a core layer over the cladded bottom.

Abstract: To balance the wheel which is formed of a rolled plate. A wheel having a disk which is formed by dividing the rolled plate into plural at the rolling direction, wherein balance of wheel is adjusted by controlling the angle between the direction which goes to the thick part from the center of the disk and the direction of the air valve insertion hole, and the direction of the air valve insertion hole is certainly accord with the heaviest point by agreeing the direction of the air valve insertion hole with the direction of the thick part.

Abstract: A steering system of a motorcycle in which a top bridge is rotatably attached to a head pipe. An approximately flat plate handle bracket is attached to the top bridge through cushioning members. The flat plate handle bracket covers substantially the entire upper surface of the top bridge. Right and left handlebars are attached to the handlebar bracket.

Abstract: On a waveguide 34 formed on a substrate 33, a plurality of comblike shaped electrodes 37, 38 that generate surface acoustic waves 37a, 38a from different directions are provided. And a periodic refractive indices portion 40 is formed, where the refractive indices are periodically distributed in accordance with the wavelengths of the surface acoustic waves 37a, 38a generated by applying a voltage to the comblike shaped electrodes 37, 38. And by changing a frequency of the applying voltage for sequentially changing the wavelengths of the surface acoustic waves 37a, 38a, the exiting direction of the light exiting from the periodic refractive indices portion 40 is scanned. This makes it possible to provide an optical functional device and an optical scanning apparatus that perform light scanning less costly but at a high speed, and that can secure a wide scanning angle.

Abstract: An optical module has a substrate, a waveguide, formed on the substrate, for guiding light, and a photonic crystal portion that has media having different refractive indices arranged in a periodic pattern and that is disposed in a channel of the waveguide on the substrate. Here, the photonic crystal and the substrate are integrally formed.