Abstract: A polarization beam splitter is disclosed having reduced size and weight relative to the prior art. The disclosed polarization beam splitter has a translucent substrate and a hologram layer provided on a front surface of the substrate. The polarization beam splitter is capable of separating S-polarized light from light incident on the hologram layer via the substrate, wherein the substrate has a back surface facing the front surface on which the hologram layer is provided, and a side surface connecting the front surface and the back surface. The hologram layer has a hologram for diffracting circularly polarized light incident on the hologram layer from outside the substrate via either the back surface or a portion of the side surface to generate S-polarized light having an extinction ratio of 50:1 or greater toward the other of the back surface or the portion of the side surface.

Abstract: A polarization beam splitter is disclosed having reduced size and weight relative to the prior art. The disclosed polarization beam splitter has a translucent substrate and a hologram layer provided on a front surface of the substrate. The polarization beam splitter is capable of separating S-polarized light from light incident on the hologram layer via the substrate, wherein the substrate has a back surface facing the front surface on which the hologram layer is provided, and a side surface connecting the front surface and the back surface. The hologram layer has a hologram for diffracting circularly polarized light incident on the hologram layer from outside the substrate via either the back surface or a portion of the side surface to generate S-polarized light having an extinction ratio of 50:1 or greater toward the other of the back surface or the portion of the side surface.

Abstract: A light-concentrating mechanism comprises an angle-selective reflection means that reflects light having an incident angle of at least a first threshold angle and transmits at least some of the light having an incident angle smaller than the first threshold angle, and an angle-increase reflection means that reflects incident light at an angle greater than the incident angle of said light, the two means being arranged to have a gap therebetween. The angle-increase reflection means reflects, at an angle equal to or greater than the first threshold angle, at least some of the light transmitted by the angle-selective reflection means, and the angle-selective reflection means reflects the light reflected by the angle-increase reflection means and has an angle that is equal to or greater than the first threshold angle. Light is propagated and concentrated by the gap between the angle-selective reflection means and the angle-increase reflection means.

Abstract: [Problem] To provide a light-concentrating mechanism that is suitable for photovoltaic power generation. [Solution] This light-concentrating mechanism comprises an angle selective reflection means that reflects light having an incident angle of at least a first threshold angle and transmits at least some of the light having an incident angle smaller than the first threshold angle, and an angle-increase reflection means that reflects incident light at an angle greater than the incident angle of said light, the two means being arranged so as to have a gap therebetween.

Abstract: To provide a photovoltaic device and a light condensing device having a high condensing rate which can be manufactured easily and at low cost. This light condensing device is provided with: a light-guiding subtract for causing light to propagate between a rear-side surface and a front-side surface for receiving light from a light source; a reflective layer for light guiding, in which a reflection-type hologram is formed for reflecting light incident at a first incidence angle less than the critical angle of the light-guiding substrate at a reflection angle greater than the critical angle, the reflective layer being provided to the rear-side surface; and an emission window for causing light incident at a second incidence angle equal to or greater than the critical angle to be emitted from the light-guiding substrate, the emission window being provided to the front-side surface and/or the rear-side surface.

Abstract: A three-dimensional image projector includes: a conversion optical system including a plate-shaped first optical member that has an incidence surface is incident, and an emission surface and that converts a traveling direction of the image light so as to form a predetermined angle between the emission surface and an emission direction of the image light on the emission surface; a rotary driving unit that drives the conversion optical system so as to rotate along the emission surface with a predetermined point on the emission surface as the center of rotation; and an image projection unit that is erected along a rotation axis, converts the traveling direction of the image light emitted from the conversion optical system into a first direction along a surface crossing the rotation axis, and diffuses the image light emitted from the conversion optical system in a second direction along the rotation axis.

Abstract: [Problem] To provide a low-cost, high-precision three-dimensional shape measuring device using vibration-resistant phase shift digital holography.

Abstract: [Problem] To provide a light-concentrating mechanism that is suitable for photovoltaic power generation. [Solution] This light-concentrating mechanism comprises an angle selective reflection means that reflects light having an incident angle of at least a first threshold angle and transmits at least some of the light having an incident angle smaller than the first threshold angle, and an angle-increase reflection means that reflects incident light at an angle greater than the incident angle of said light, the two means being arranged so as to have a gap therebetween.

Abstract: [Problem] To provide a low-cost, high-precision three-dimensional shape measuring device using vibration-resistant phase shift digital holography.

Abstract: A three-dimensional image projector includes: a conversion optical system including a plate-shaped first optical member that has an incidence surface is incident, and an emission surface and that converts a traveling direction of the image light so as to form a predetermined angle between the emission surface and an emission direction of the image light on the emission surface; a rotary driving unit that drives the conversion optical system so as to rotate along the emission surface with a predetermined point on the emission surface as the center of rotation; and an image projection unit that is erected along a rotation axis, converts the traveling direction of the image light emitted from the conversion optical system into a first direction along a surface crossing the rotation axis, and diffuses the image light emitted from the conversion optical system in a second direction along the rotation axis.

Abstract: An authentication system includes a first hologram, a second hologram, a light source, and an image pickup device. In this case, the first hologram is a transmission hologram for causing interference with data of the second hologram in order to authenticate the second hologram, the second hologram is a reflection hologram to be authenticated, and light from the light source is reflected by the second hologram, the reflected light is irradiated to the first hologram as reference light for the first hologram. Diffracted light through the first hologram is acquired by the image pickup device to authenticate the second hologram.

Abstract: The invention provides a hologram generating device and a hologram generating method that allows the generation of a hologram for reproducing an easily observable three-dimensional image without restrictions on object sizes. The hologram generating device includes an object light generation means, a reference light generation means, an irradiation means, a polarization light selecting reflection means, and a polarization conversion means, wherein the one of the object light and the reference light incident from the rear surface is made to interfere with the other of the object light and reference light incident from the front surface in the hologram recording layer to record a reflection type hologram on the hologram recording layer.

Abstract: An object of the present invention is to display a highly reproducible three-dimensional image in response to changes in the viewer's position and to easily realize the miniaturization of the system. The three-dimensional image projector includes a projection image forming disc in which a hologram recording medium is formed along a disc-shaped glass substrate, and which projects image light having directivity by causing the image light to fall incident on the hologram recording medium, and a rotational drive unit for rotationally driving the projection image forming disc along a surface of the glass substrate with the center point on the surface as a rotation center. The projection image forming disc is preliminarily recorded with a hologram by causing two laser beams as reference light and object light to simultaneously fall incident on the hologram recording medium.

Abstract: Provided is a three-dimensional image projector capable of displaying a highly reproducible three-dimensional image in response to changes in a viewer's position and easily accomplishing system downsizing.

Abstract: Described is a device and method that makes it possible to acquire image information required for displaying a three-dimensional image of an object in a space with a simple configuration and to achieve display of a stereoscopic dynamic image in a true sense with a simple configuration. Light from an object (10) impinges upon a deflecting plate (11). Among the incident beams of light, the deflecting plate (11) allows beams of light at a predetermined angle to the plane of the deflecting plate (11) to pass, the beams exiting as parallel beams of light perpendicular to the plane of the deflecting plate (11). The light passes through a converging lens (12), a pinhole member (13), and a converging lens (14) to impinge upon a CCD (15). An angle of incident light selected by the deflecting plate (11) is sequentially changed as time passes.

Abstract: A search method of efficiently retrieving information is provided. A search light 21 is generated from a search condition (S1). The search light is irradiated onto a hologram 104a recorded in a hologram recording layer 104 (S2). When the search light interferes with the hologram and a reproduction light is generated, address information of the hologram from which the reproduction light is generated is identified using an address light 23 that reads the address information. The identified address light is recorded (S3). When the search light does not generate the reproduction light from the hologram, the search light is irradiated onto another hologram 104b recorded in the hologram recording layer.

Abstract: [Object] Provided are a hologram generating device and a hologram generating method that allows the generation of a hologram for reproducing an easily observable three-dimensional image without restrictions on object sizes.

Abstract: An optical information recording device, a reproduction device, and a method enabling include a first spatial light modulator I for generating information light by spatially modulating light from a light source 143 by a plurality of pixels and a second spatial light modulator R for generating reference light by spatially modulating light from a light source by a plurality of pixels. The area I of the information light and the area R of the reference light on the entrance pupil surface of an objective lens 111 are formed such that one area surrounds the other area. The reference light is spatially modulated by the second spatial light modulator R such that interference is not easily generated between the reference lights in the information recording layer 3.

Abstract: An object of the present invention is to display a highly reproducible three-dimensional image in response to changes in the viewer's position and to easily realize the miniaturization of the system. The three-dimensional image projector 1 includes a projection image forming disc 4 in which a hologram recording medium 9 is formed along a disc-shaped glass substrate 8a, and which projects image light having directivity by causing the image light to fall incident on the hologram recording medium 9, and a rotational drive unit 3 for rotationally driving the projection image forming disc 4 along a surface of the glass substrate 8a with the center point C1 on the surface as a rotation center. The projection image forming disc 4 is preliminarily recorded with a hologram 11 by causing two laser beams L2, L3 as reference light and object light to simultaneously fall incident on the hologram recording medium 9.

Abstract: Provided is an optical information recording method and an optical information recording medium, which can achieve easy duplication in holographic recording. The optical information recording method is for recording information to an optical information recording medium 4 which includes an information recording layer to which information is recorded using holography. In the method, virtual information light 6 composed of information light 2 to which information is added by spatially modulating at least a part of light ray flux emitted from a light source and of recording-specific reference light 3 is generated, and virtual information light 6 and virtual recording-specific reference light 8 are irradiated onto the information recording layer so that information is recorded thereto by interference pattern generated by interference between virtual information light 6 and virtual recording-specific reference light 8.