Abstract: When an end-face-emitting photonic crystal laser element 10 is seen in an X axis, one end of an upper electrode E2 overlaps a laser light exit surface SF, the upper electrode E2 and an opposite end face SB are separated from each other, the upper electrode E2 is separated from both lateral end faces SR, SL, and one end of an active layer 3B overlaps the laser light exit surface SF.

Abstract: According to a finite difference between inverse numbers of arrangement periods (a1 and a2) in first and second periodic structures, when seen in a thickness direction of a semiconductor laser element, at least two laser beams that form a predetermined angle (??) with respect to a lengthwise direction of a first driving electrode (E2) are generated in the semiconductor laser element, one of the laser beams is set to be totally reflected in a light emission end surface, and a refractive angle (?3) of the other laser beam is set to be less than 90 degrees.

Abstract: A photonic crystal laser capable of producing a radially-polarized halo-shaped laser beam having a smaller width than conventional beams includes: an active layer; a ring-shaped photonic crystal including a plate-shaped base body on one side of the active layer, the base body having a number of modified refractive index areas of the same shape, the modified refractive index areas having a refractive index different from the base body and periodically arranged in the circumferential direction of a ring, and each of the modified refractive index areas being asymmetrically shaped with respect to an axis extending through the center of the modified refractive index area in the radial direction of the ring; a first and second electrode facing each other across the active layer and the ring-shaped photonic crystal; and a window provided in the second electrode capable of allowing passage of a laser light generated from the ring-shaped photonic crystal.

Abstract: A semiconductor light emitting element includes an electrode 8, an active layer 3, a photonic crystal layer 4, and an electrode 9. Conductivity types between the active layer 3 and the electrode 8 and between the active layer 3 and the electrode 9 differ from each other. The electrode 8, the active layer 3, the photonic crystal layer 4, and the electrode 9 are stacked along the X-axis. The X-axis passes through a central part 8a2 of the opening 8a when viewed from the axis line direction of the X-axis. The end 9e1 of the electrode 9 and the end 8e1 of the opening 8a substantially coincide with each other when viewed from the axis line direction of the X-axis.

Abstract: A two-dimensional photonic crystal surface emitting laser light source includes a two-dimensional photonic crystal made of a plate-shaped body material provided with a periodic arrangement of identically-shaped holes and an active layer. The hole is not located on a first half-line extending from the gravity center of the hole, while the hole is located on a second half-line extending in the direction opposite to the first half-line. Injecting electric charges into the active layer generates light, which creates an electric field encircling the gravity center. For a given point on the second half-line where the hole is located, there is no hole at a point that is symmetrical to the aforementioned point with respect to the gravity center, so that the electric field vectors at the two points do not cancel each other and the laser light is stronger than conventional examples.

Abstract: According to a finite difference between inverse numbers of arrangement periods (a1 and a2) in first and second periodic structures, when seen in a thickness direction of a semiconductor laser element, at least two laser beams that form a predetermined angle (??) with respect to a lengthwise direction of a first driving electrode (E2) are generated in the semiconductor laser element, one of the laser beams is set to be totally reflected in a light emission end surface, and a refractive angle (?3) of the other laser beam is set to be less than 90 degrees.

Abstract: When an end-face-emitting photonic crystal laser element 10 is seen in an X axis, one end of an upper electrode E2 overlaps a laser light exit surface SF, the upper electrode E2 and an opposite end face SB are separated from each other, the upper electrode E2 is separated from both lateral end faces SR, SL, and one end of an active layer 3B overlaps the laser light exit surface SF.

Abstract: A semiconductor surface light-emitting element of this invention is provided with a photonic crystal layer 6 obtained by periodically forming a plurality of holes H in a basic layer 6A comprised of a first compound semiconductor of the zinc blend structure and growing embedded regions 6B comprised of a second compound semiconductor of the zinc blend structure, in the holes H, and an active layer 4 to supply light to the photonic crystal layer 6, in which a principal surface of the basic layer 6A is a (001) plane and in which side faces of each hole H have at least three different {100} facets.

Abstract: The present edge-emitting semiconductor layer element includes two-dimensional photonic crystals 4 formed in a semiconductor layer, and when one direction of a contact region of an electrode 8 is provided as a length direction (X-direction) and a direction perpendicular to both of the length direction and a thickness direction of a substrate is provided as a width direction (Y-direction), the two-dimensional photonic crystals 4 are, when viewed from a direction (Z-axis) perpendicular to the substrate, located in a region containing the electrode contact region and wider in the width direction than the contact region, and have a refractive index periodic structure in which the refractive index satisfies a Bragg's diffraction condition while periodically changing at every interval along the one direction (X-axis).

Abstract: A semiconductor surface light-emitting element of this invention is provided with a photonic crystal layer 6 obtained by periodically forming a plurality of holes H in a basic layer 6A comprised of a first compound semiconductor of the zinc blende structure and growing embedded regions 6B comprised of a second compound semiconductor of the zinc blende structure, in the holes H, and an active layer 4 to supply light to the photonic crystal layer 6, in which a principal surface of the basic layer 6A is a (001) plane and in which side faces of each hole H have at least three different {100} facets.

Abstract: A photonic crystal laser capable of producing a radially-polarized halo-shaped laser beam having a smaller width than conventional beams includes: an active layer; a ring-shaped photonic crystal including a plate-shaped base body on one side of the active layer, the base body having a number of modified refractive index areas of the same shape, the modified refractive index areas having a refractive index different from the base body and periodically arranged in the circumferential direction of a ring, and each of the modified refractive index areas being asymmetrically shaped with respect to an axis extending through the center of the modified refractive index area in the radial direction of the ring; a first and second electrode facing each other across the active layer and the ring-shaped photonic crystal; and a window provided in the second electrode capable of allowing passage of a laser light generated from the ring-shaped photonic crystal.

Abstract: A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.

Abstract: A laser capable of emitting multiple laser beams is provided. A two-dimensional photonic crystal laser according to the present invention has a laminated structure including an active layer, a first photonic crystal layer having a periodic distribution of refractive index with a first period, and a second photonic crystal layer having a periodic distribution of refractive index with a second period that differs from the first period. This two-dimensional photonic crystal laser can emit a main beam traveling in a direction perpendicular to the two-dimensional photonic crystals and side beams each traveling in a direction inclined with respect to the main beam. These beams can be used, for example, in a recording/reproducing device by means of an optical disk, the main beam being used for recording/reproducing information and the side beams for following up the track.

Abstract: A two-dimensional photonic crystal laser light is provided. The two-dimensional photonic crystal laser includes a two-dimensional photonic crystal made of a plate-shaped member provided with a periodic arrangement of identically-shaped modified refractive index areas having a refractive index different from that of the plate-shaped member; and an active layer provided on one side of the two-dimensional photonic crystal. The modified refractive index areas are arranged at lattice points of a lattice with a same period at least in two directions; each modified refractive index area is shaped so that a feedback strength is different with respect to directions of two primitive lattice vectors of the lattice; the two-dimensional photonic crystal has a periodic structure of a supercell, which contains a plurality of lattice points; and the sum of the feedback strengths by all modified refractive index areas in the supercell is identical in each direction of the two primitive lattice vectors.

Abstract: The two-dimensional photonic crystal surface emitting laser according to the present invention includes a number of main modified refractive index areas periodically provided in a two-dimensional photonic crystal and secondary structures each relatively located in a similar manner to each of the main modified refractive index areas. The location of the secondary structure is determined so that a main reflected light which is reflected by a main modified refractive index area and a secondary reflected light which is reflected by a secondary structure are weakened or intensified by interference.

Abstract: An LED light source is formed of an LED and an angle control lens. The angle control lens includes a transparent member in a shape of a rotational symmetry, and includes a center convex curved surface area (light-emission area) A1, a peripheral curved surface area (light-emission area) B1, a peripheral curved surface reflection area C1, a center concave curved surface area (light-incidence area) D, and a convex curved surface area E formed between the areas A1, B1. The convex curved surface area E is formed in a position for receiving direct incoming light from the LED (direct incoming light deviated from the center portion), and is optically constructed to anteriorly emit this received light (in a direction intended to be emitted as a result of a light-emission angle being controlled).

Abstract: A two-dimensional photonic crystal surface emitting laser light source according to the present invention includes a two-dimensional photonic crystal made of a plate-shaped body material provided with a periodic arrangement of identically-shaped holes 242A and an active layer provided on one side of the two-dimensional photonic crystal. The hole 242A is not located on a first half-line 251 extending from the gravity center G1 of the hole in a direction within the plane of the two-dimensional photonic crystal, while the hole 242A is located at least on a portion of a second half-line 252 extending from the gravity center G1 in the direction opposite to the first half-line 251. Injecting electric charges into the active layer generates light, which creates an electric field that encircles the gravity center G1 within the two-dimensional photonic crystal.

Abstract: A laser capable of emitting multiple laser beams is provided. A two-dimensional photonic crystal laser according to the present invention has a laminated structure including an active layer, a first photonic crystal layer having a periodic distribution of refractive index with a first period, and a second photonic crystal layer having a periodic distribution of refractive index with a second period that differs from the first period. This two-dimensional photonic crystal laser can emit a main beam traveling in a direction perpendicular to the two-dimensional photonic crystals and side beams each traveling in a direction inclined with respect to the main beam. These beams can be used, for example, in a recording/reproducing device by means of an optical disk, the main beam being used for recording/reproducing information and the side beams for following up the track.

Abstract: A reflection mixing member (13) has an alignment in which light from a first light source is incident on a reflecting surface (13a) and light from a second light source is incident on a reflecting surface (13b). A relationship between a pitch Wp, which is a pitch between portions (triangular prisms) respectively formed of the reflecting surface (13a) and the reflecting surface (13b) in the reflection mixing member (13), and a lens pitch Wf is set to be (Wp/Wf?1). As a result, light fluxes of respectively different distribution are incident on each lens portion of fly's eye lens 14a, so that it is possible to prevent luminance non-uniformity in light incident on a liquid crystal display panel (5) from being generated and prevent color non-uniformity from being generated on a screen at the same time.

Abstract: A projection type video display apparatus is provided with an LED array for emitting light in red, an LED array for emitting light in green, and an LED array for emitting light in blue. On a light-incident side of a rod integrator, time-dividing mirrors 2A, 2B arranged in a cross manner, for guiding the light from each LED array to an inside of the rod integrator, are arranged. Furthermore, on a light-emission side of the LED array for emitting the light in red, a time-diving mirror is arranged, and on a light-emission side of the LED array for emitting the light in blue, a time-dividing mirror is provided. Each time-dividing mirror switch either to reflect the light or to transmit the light, depending on whether or not voltage is applied thereto. At time-dividing lighting timing of the LED arrays, the time-dividing mirrors switch either to reflect the light or to transmit the light.