Abstract: The present invention provides a windshield that has a display region onto which information is projected using light emitted from a head-up display device, the windshield including an outer glass plate, an inner glass plate that is arranged opposite to the outer glass plate, and an interlayer that is arranged between the outer glass plate and the inner glass plate, wherein lattice points are defined at a pitch of no greater than 20 mm in the display region, and when wedge angles at the lattice points are measured using an interferometer with 240×240 pixels or more, a difference between the largest value and the smallest value of the wedge angles is no greater than 0.32 mrad.

Abstract: A fluorescence light detection device includes an excitation light fiber having an excitation light emitting end configured to emit excitation light; a fluorescence light fiber having a fluorescence light incident end on which fluorescence light is incident; an objective lens arranged between where the excitation light emitting end and the fluorescence light incident end are located, and a sample; and a reflective member arranged between where the excitation light emitting end and the fluorescence light incident end are located, and the objective lens, and having two reflective surfaces facing in opposite directions. The two reflective surfaces of the reflective member are positioned between an optical axis of the excitation light fiber and an optical axis of the fluorescence light fiber.

Abstract: A fluorescence light detection device includes an excitation light fiber having an excitation light emitting end configured to emit excitation light; a fluorescence light fiber having a fluorescence light incident end on which fluorescence light is incident; an objective lens arranged between where the excitation light emitting end and the fluorescence light incident end are located, and a sample; and a reflective member arranged between where the excitation light emitting end and the fluorescence light incident end are located, and the objective lens, and having two reflective surfaces facing in opposite directions. The two reflective surfaces of the reflective member are positioned between an optical axis of the excitation light fiber and an optical axis of the fluorescence light fiber.

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: Provided is an antireflection structural body including a substrate having a property of transmitting light in a wavelength range to be used and an antireflection layer arranged on the substrate. This structural body exhibits high antireflection performance, and provides a high degree of freedom in selecting a material to be used for the antireflection layer regardless of the refractive index of the substrate. The antireflection layer has a periodic structure of an arrangement of projections. The period of the arrangement of the projections in the antireflection layer is not greater than the shortest wavelength of the above wavelength range. A low refractive index layer having a lower refractive index than that of the substrate is arranged between the substrate and the antireflection layer.

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 exhibits at least one of an upconversion emission characteristic and a light amplifying characteristic when irradiated with an excitation light. The optical element includes a bulk glass that contains titanium oxide as a main component, and the glass further contains a rare earth element. As the rare earth element, at least one element of Er and Yb, or a combination of Yb and Tm preferably is used, for example.

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: 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 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 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: 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 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.

Abstract: A photonic crystal waveguide and a homogeneous medium waveguide for enabling a steep bend and arrangement at an arbitrary angle with low propagation loss. A photonic crystal waveguide has a core formed by a photonic crystal having periodicity in the Y-direction. Electromagnetic wave is propagated by a band on the Brillouin zone boundary of the photonic band structure of the core. A side face of the core parallel to the Y-direction is in contact with a homogeneous medium having a refractive index of ns, and the condition of ?0/ns>a?/(?2/4+a2)0.5 is satisfied when the wavelength in vacuum of the electromagnetic wave is represented by ?0, the period of the photonic crystal is represented by a, and the period in the XZ-plane direction of the wave propagated through the core is represented by ?.

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: In a waveguide element using a photonic crystal including a core formed of a photonic crystal having a refractive index periodicity in at least two directions perpendicular to a propagation direction of an electromagnetic wave and a cladding arranged in contact with the core in order to confine the electromagnetic wave in the core, an incident side phase modulation portion is provided for allowing an electromagnetic wave that is coupled to a band on or near a Brillouin zone boundary in a photonic band structure in the core and propagates in the core to enter the core.

Abstract: A filter module is provided for an optical communications system. The filter module includes a lens, three optical fibers, an optical filter, and a mirror. The three optical fibers are arranged on a single side of the lens. The lens includes a first face coated with the optical filter and that faces the mirror. The optical fibers are arranged on a second face of the lens. A cascade of the filter modules are configured to connect and form a multiplexing/demultiplexing unit.

Abstract: In a waveguide element using a photonic crystal including a core formed of a photonic crystal having a refractive index periodicity in at least two directions perpendicular to a propagation direction of an electromagnetic wave and a cladding arranged in contact with the core in order to confine the electromagnetic wave in the core, an incident side phase modulation portion is provided for allowing an electromagnetic wave that is coupled to a band on or near a Brillouin zone boundary in a photonic band structure in the core and propagates in the core to enter the core.