Abstract: A far-infrared lens system is used for far-infrared wavelengths, and configures two lenses comprising, in the order from an object side, a first positive lens and a second positive lens. A refractive ratio of a lens material configuring the greatest core thickness in each lens is greater than 2.0 and less than or equal to 3.9 at a wavelength of 10 ?m. A conditional expression 2.50<f1/f<7.40 is satisfied, where f1 represents a focal distance of a first lens L1, and f represents a focal distance of an entire far-infrared lens system LN. The half field of view ? of the far-infrared lens system is greater than 30°.

Abstract: Disclosed is a deflection optical element, which makes it possible to deflect an incident light so as to couple the incident light to an optical element disposed in the later stage without deteriorating the optical efficiency. The deflection optical element, which deflects an incident light coming along a first optical axis at a deflection surface and emits an emission light propagating along a second optical axis so as to couple the emission light to either a diffraction grating or a refracting optical system, comprises at least one diffracting surface and at least one reflecting surface, wherein the angle ?n, an angle ?t derived as a total diffraction angle caused by the at least one diffracting surface, and an angle ?a, which is formed at a second intersection of the first optical axis and the second optical axis, fulfill a conditional relationship of: 0??n<?a<?t.

Abstract: A recorder has a recording medium for information recording, a light source, an optical system, a slider, and an optical waveguide. To the optical system, light from the light source enters, and the slider moves relative to the recording medium while not in contact therewith. The optical waveguide is arranged at position facing the recording medium in the slider so that light entering from the optical system is irradiated on the recording medium. Where the mode field diameter of the optical waveguide on the light output side is d and the mode field diameter thereof on the light input side is D, the mode field diameter is converted by smoothly changing the diameter of the optical waveguide to satisfy D>d.

Abstract: Provided is an optical recording head in which a light beam from a light source is collected by an optical element and reflected on a reflecting surface to be formed into a spot light. Since a support portion for supporting the light source of the optical element at a predetermined position and the reflection surface for reflecting the light beam are formed integrally with each other, it is not required to perform the positioning thereof, and light can be collected to a very small spot with high efficiency, and an optical recording head and an optical recording apparatus having low heights can be provided.

Abstract: A surface light emitter comprising a surface-emitting device is notably increased in the front brightness of light outputted from the surface-emitting device. In the surface light emitter comprising the surface-emitting device 20 and a light control sheet 10, a repetitive concavo-convex pattern of trapezoidal from in section is formed at least on one side of the light control sheet and has planar portions 12a at distal ends of projections of the concavo-convex pattern tightly bonded to an output surface 21a of the surface-emitting device. The light control sheet satisfies a condition 0.75>D>4[(sin ??1/n)2+0.

Abstract: Provided is an optical device configured to makes it possible to enhance use efficiency of light. An optical device is provided with an optical element to deflect incident light and a fixation member on which the optical element is fixed. The optical element includes a reflective surface and a diffraction grating surface that deflects the incident light. The optical element is fixed on the fixation member to restrain displacement in accordance with temperature changes at portions thereof other than the reflective surface and the diffracting grating surface in such a condition that displacement is caused without restraint be temperature changes at the reflective surface and the diffraction grating surface. A change of the incident light in the deflection angle due to an inclination change by the reflective surface and the diffracting grating surface is suppressed by a change in a diffraction angle due to a periodical change in the diffraction grating by the displacement of the diffraction grating surface.

Abstract: An optical recording head to record information onto a recording medium utilizing light including; a slider provided to move relatively to the recording medium; a light propagation element provided on a side surface of the slider substantially vertical against a recording surface of the recording medium so as to cause propagation of light incident with a predetermined angle to be irradiated on the recording medium; and, a prism provided on the light propagation element so as to oppose to the side surface of the slider having the light propagation element and to deflect the incident light to be incident into the light propagation element with a predetermined angle.

Abstract: Disclosed is a deflection optical element, which makes it possible to deflect an incident light so as to couple the incident light to an optical element disposed in the later stage without deteriorating the optical efficiency. The deflection optical element, which deflects an incident light coming along a first optical axis at a deflection surface and emits an emission light propagating along a second optical axis so as to couple the emission light to either a diffraction grating or a refracting optical system, comprises at least one diffracting surface and at least one reflecting surface, wherein the angle ?n, an angle ?t derived as a total diffraction angle caused by the at least one diffracting surface, and an angle ?a, which is formed at a second intersection of the first optical axis and the second optical axis, fulfill a conditional relationship of: 0??n<?a<?t.

Abstract: Proposed is a technique of guiding light to a waveguide, by which the light use efficiency is increased. In order to achieve the above object, adopted is an optical element comprising, at an outer edge portion thereof, an incident surface on which light from a light source is incident, a diffraction grating surface, and an internal reflection surface which guides light incident from the incident surface to the diffraction grating surface.

Abstract: A recorder has a recording medium for information recording, a light source, an optical system, a slider, and an optical waveguide. To the optical system, light from the light source enters, and the slider moves relative to the recording medium while not in contact therewith. The optical waveguide is arranged at position facing the recording medium in the slider so that light entering from the optical system is irradiated on the recording medium. Where the mode field diameter of the optical waveguide on the light output side is d and the mode field diameter thereof on the light input side is D, the mode field diameter is converted by smoothly changing the diameter of the optical waveguide to satisfy D>d.

Abstract: A front luminance of light emitted from a surface light emitting apparatus having a surface light emitting element is greatly improved. The surface light emitting apparatus is provided with a surface light emitting element (20) and a photochromic sheet (10). A repeated uneven pattern having a cross section in a trapezoidal shape is arranged at least on one side of the photochromic sheet, a flat portion (12a) at the tip on the protruding side of the unevenness is adhered to an emitting surface (21a) of the surface light emitting element, and conditions of 0.75>D>4[(sin ??1/n)2+0.034] are met, where, ? is an apex angle formed by facing inclined surfaces protruded in a trapezoidal shape of the photochromic sheet, n is a refractive index of the photochromic sheet, and D is a ratio of the length of the surface light emitting element at a portion adhered to the emitting surface to the length of at least one cycle of the unevenness in an arrangement direction.

Abstract: A thermal-assisted magnetic recording head which heats a magnetic bit of a magnetic disk by light radiation in recording magnetic data into the magnetic disk with a magnetic writing element. The magnetic recording head has a reflecting converging element with a surface emitting laser incorporated therein, and a transparent plate serving as a slider. A laser beam emitted from the surface emitting laser is reflected by a mirror surface of the reflecting converging element and is converged on a plasmon probe formed on a bottom surface of the transparent plate. Thereby, near-field light effuses from the plasmon probe into a very small area and heats the magnetic bit of the magnetic disk.

Abstract: An optical head includes: a slider which moves relative to a recording medium while the slider is floating above the recording medium; an optical waveguide which is provided on a side surface of an end portion of the slider and which has the focusing function of forming a light spot on the recording medium; and a light guide optical system that guides a light pencil to the optical waveguide. A light pencil coupling portion which receives the light pencil from the light guide optical system is provided in a surface parallel to a direction in which the light pencil is guided by the optical waveguide; and a reflective surface which deflects the light pencil to the light pencil coupling portion is provided in the light guide optical system. The light pencil coupling portion has the function of correcting aberration resulting from oblique incidence of the light pencil obliquely incident from the light guide optical system.

Abstract: A recorder has a recording head which uses light for information recording to a recording medium. The recording head has a slider and an optical waveguide. The slider moves relative to the recording medium while floating thereon. The optical waveguide is provided in the slider and has a refractive index difference of 20% or more between a core and a cladding.

Abstract: The front luminance of the light emitted from a surface light emitter provided with a surface light emitting device is greatly enhanced. In a surface light emitter in which a light control sheet 10 having a concavoconvex structure provided on one of its surfaces is affixed on to the light emitting side surface of a surface light emitting device, the projections 12 on one surface of the above light control sheet gets small towards the light emitting side surface of the above surface light emitting device, not only the tip surfaces 12a of these projections 12 are affixed to the light emitting side surface, but also a transparent material with a lower refractive index than the above light control sheet is packed in the space part 13 formed between the projections of the above light control sheet and the light emitting side surface of the surface light emitting device.

Abstract: An optical recording head simply structured, enabling a reduction in thickness, and having sufficient efficiency even if a light source with small output is used when a plasmon probe is used. The optical recording head includes a light source section for emitting light, a slider moving relative to a recording medium, and an optical waveguide disposed in the slider, guiding the light from the light source section and irradiating the surface of the recording medium with the light, and having a light emission angle not perpendicular to the surface, of the slider, facing the surface of the recording medium.

Abstract: Provided is an optical recording head in which a light beam from a light source is collected by an optical element and reflected on a reflecting surface to be formed into a spot light. Since a support portion for supporting the light source of the optical element at a predetermined position and the reflection surface for reflecting the light beam are formed integrally with each other, it is not required to perform the positioning thereof, and light can be collected to a very small spot with high efficiency, and an optical recording head and an optical recording apparatus having low heights can be provided.

Abstract: In the present invention, provided is a surface light emitter in which an amount of light emitted from the surface light emitter and front luminance are designed to be increased, and generation of moire images is also designed to be inhibited, and also provided is a display device employing the surface light emitter as a backlight. Also disclosed is a surface light emitter possessing at least a light control sheet and a surface light-emitting device, wherein the light control sheet comprises protrusions provided on a surface of the light control sheet, and tip portions of the protrusions are attached to a light emission surface of the surface light-emitting device through an adhesion layer, and wherein the light control sheet has a haze value of at least 85%.

Abstract: An optical head which has a prism with an incident section, an internal reflective surface and an emergent surface, and an optical head device which employs the optical head. Light emitted from a light source is incident to the prism through the incident section, reflects at least once on the internal reflective surface and is converged in the vicinity of the emergent surface. Then, the light effuses through the emergent surface as near field light.

Abstract: A surface luminous body having at least a surface luminous element and a light regulating sheet characterized in that the light regulating sheet has a plurality of protrusions at least on one side thereof, and ends of the protrusions are in contact with an light outgoing surface of the surface luminous element via an adhesion layer, and the adhesion layer has one or more pressure-sensitive adhesion layers composed of one or more kinds of pressure-sensitive adhesives, and the ends of the protrusions are embedded partially into the adhesion layer, and the average thickness of the one or more pressure-sensitive adhesion layers between the ends of the protrusions and the light outgoing surface of the surface luminous element is less than 50% of the total thickness of at least one pressure-sensitive adhesion layer composed of at least one kind of pressure-sensitive adhesive.