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.