Abstract: A two-dimensional photonic crystal laser includes: electrodes; an active layer; and a two-dimensional photonic crystal layer in which modified refractive index regions are disposed to be shifted by different shift amounts from respective lattice points or/and are disposed at the respective lattice points with different areas, the shift amount or/and the area is/are modified with a composite modulation period and expressed by a modulation phase ?(r?) expressed using a vector r? indicating a position of each lattice point of the two-dimensional lattice, a vector kn? indicating a combination of an inclination angle and an azimuthal angle of each of n laser beams mutually differing in the inclination angle and/or the azimuthal angle, and an amplitude An and a phase exp(i?n) determined for each n and the amplitude An and/or the phase exp(i?n) for each value of n differ(s) from each other in at least two different values of n.

Abstract: A photonic-crystal surface emitting laser includes a first semiconductor layer, a photonic crystal layer having a refractive index higher than a refractive index of the first semiconductor layer and provided on the first semiconductor layer, and an active layer provided opposite to the first semiconductor layer with respect to the photonic crystal layer. The photonic crystal layer has a first region and a plurality of second regions each having a refractive index different from a refractive index of the first region and periodically disposed in the first region in a plane of the photonic crystal layer. The second regions extend from the photonic crystal layer to the first semiconductor layer.

Abstract: A two-dimensional photonic-crystal laser includes: a substrate made of an n-type semiconductor; a p-type cladding layer on an upper side of the substrate made of a p-type semiconductor; an active layer on an upper side of the cladding layer; a two-dimensional photonic-crystal layer on an upper side of the active layer including a plate-shaped base body made of an n-type semiconductor wherein modified refractive index areas whose refractive index differs from the base body are arranged; a first tunnel layer between the substrate and cladding layer made of an n-type semiconductor having a carrier density higher than the substrate's; a second tunnel layer between the first tunnel and cladding layers, made of a p-type semiconductor having a carrier density higher than the p-type semiconductor layer's; a first electrode on a lower side of or in the substrate; and a second electrode on an upper side of the two-dimensional photonic-crystal layer.

Abstract: A surface emission laser formed of a group III nitride semiconductor includes a first conductivity type first clad layer; a first conductivity type first guide layer on the first clad layer; a light-emitting layer on the first guide layer; a second guide layer on the light-emitting layer; and a second conductivity type second clad layer on the second guide layer. The first or second guide layer internally includes voids periodically arranged at square lattice positions with two axes perpendicular to one another as arrangement directions in a surface parallel to the guide layer. The voids have a polygonal prism structure or an oval columnar structure with a long axis and a short axis perpendicular to the long axis in the parallel surface, and the long axis is inclined with respect to one axis among the arrangement directions of the voids.

Abstract: A two-dimensional photonic-crystal surface-emitting laser includes an active layer, a two-dimensional photonic crystal, and electrodes. The two-dimensional photonic crystal contains a plate-shaped base material arranged on one side of the active layer and different refractive index portions arranged at lattice points of a predetermined lattice in the base material and having a refractive index different from that of the base material, a band edge frequency for each position in an electric current supply region, which is at least a part of the two-dimensional photonic crystal, is monotonically increased in one direction parallel to the base material. Such a two-dimensional photonic crystal occurs when the different refractive index portion has a refractive index smaller than that of the base material, a filling factor, which is a ratio of a volume occupied by the different refractive index portion in a unit lattice constituting the lattice, is monotonically increased in the one direction.

Abstract: A two-dimensional photonic-crystal surface-emitting laser includes an active layer; and a photonic-crystal layer including a two-dimensional photonic-crystal light-amplification portion that is a first two-dimensional photonic-crystal region provided in a plate-shaped base body disposed on one side of the active layer, and includes an amplification-portion photonic band gap which is a photonic band gap formed between two photonic bands having a band edge at a predetermined point in a reciprocal lattice space, and a two-dimensional photonic-crystal light-reflection portion that is a second two-dimensional photonic-crystal region provided around the two-dimensional photonic-crystal light-amplification portion, and includes a reflection-portion photonic band gap which is a photonic band gap formed between two photonic bands having a band edge at the predetermined point of the reciprocal lattice space, wherein energy ranges of the amplification-portion photonic band gap and the reflection-portion photonic band ga

Abstract: The 3D sensing system includes: a PC laser array in which PC laser elements are arranged on a plane; a control unit configured to control an operation mode of a laser light source; a driving unit configured to execute a drive control of the PC laser array in accordance with an operation mode controlled by the control unit; a light receiving unit configured to receive reflected light that is laser light emitted from the PC laser array and reflected from a measuring object; a signal processing unit configured to execute signal processing of the reflected light received by the light receiving unit in accordance with the operation mode; and a distance calculation unit configure to execute calculation processing of a distance to the measuring object with respect to a signal processed by the signal processing unit, in accordance with the operation mode, and to output distance data.

Abstract: A method for manufacturing a surface emitting laser made of a group-III nitride semiconductor by an MOVPE method includes: (a) growing a first cladding layer of a first conductive type on a substrate; (b) growing a first optical guide layer of the first conductive type on the first cladding layer; (c) forming holes having a two-dimensional periodicity in a plane parallel to the first optical guide layer, in the first optical guide layer by etching; (d) supplying a gas containing a group-III material and a nitrogen source and performing growth to form recessed portions having a facet of a predetermined plane direction above openings of the holes, thereby closing the openings of the holes; and (e) planarizing the recessed portions by mass transport, after the openings of the holes have been closed, wherein after the planarizing at least one side surface of the holes is a {10-10} facet.

Abstract: A surface emitting laser element formed of a group III nitride semiconductor, comprising: a first clad layer of a first conductivity type; a first guide layer of the first conductivity type having a photonic crystal layer formed on the first clad layer including voids disposed having two-dimensional periodicity in a surface parallel to the layer and a first embedding layer formed on the photonic crystal layer; a second embedding layer formed on the first embedding layer by crystal growth; an active layer formed on the second embedding layer; a second guide layer formed on the active layer; and a second clad layer of a second conductivity type formed on the second guide layer, the second conductivity type being a conductivity type opposite to the first conductivity type. The first embedding layer has a surface including pits disposed at surface positions corresponding to the voids.

Abstract: A thermal emission source is provided that has a structure capable of suppressing deterioration of an optical assembly over time. The thermal emission source includes an optical assembly (1) having an optical structure in which a member made of a semiconductor has a refractive index distribution so as to resonate with light of a wavelength shorter than a wavelength that corresponds to an absorption edge corresponding to a band gap of the semiconductor. The optical assembly (1) includes a coating structure (30) with a coating material that differs from the semiconductor of refractive portions (10) and through which light of a wavelength included in a wavelength range from visible light to far infrared rays can be transmitted.

Abstract: A surface emission laser formed of a group III nitride semiconductor includes a first conductivity type first clad layer; a first conductivity type first guide layer on the first clad layer; a light-emitting layer on the first guide layer; a second guide layer on the light-emitting layer; and a second conductivity type second clad layer on the second guide layer. The first or second guide layer internally includes voids periodically arranged at square lattice positions with two axes perpendicular to one another as arrangement directions in a surface parallel to the guide layer. The voids have a polygonal prism structure or an oval columnar structure with a long axis and a short axis perpendicular to the long axis in the parallel surface, and the long axis is inclined with respect to one axis among the arrangement directions of the voids.

Abstract: The present invention provides a thermal radiation light source that allows a wider range of material choices than those of conventional techniques, so that light having a desired peak wavelength can easily be obtained. A thermal radiation light source 10 includes a thermo-optical converter made of an optical structure in which a refractive index distribution is formed in a member 11 made of an intrinsic semiconductor so as to resonate with light of a shorter wavelength than a wavelength corresponding to a bandgap of the intrinsic semiconductor. When heat is externally supplied to the thermo-optical converter, light having a spectrum in a band of shorter wavelengths than a cutoff wavelength is produced by interband absorption in the intrinsic semiconductor, and light of a resonant wavelength ?r in the wavelength band, the light causing resonance in the optical structure, is selectively intensified and emitted as thermal radiation light.

Abstract: A method for manufacturing a surface emitting laser made of a group-III nitride semiconductor by an MOVPE method includes: (a) of growing a first cladding layer of a first conductive type on a substrate; (b) of growing a first optical guide layer of the first conductive type on the first cladding layer; (c) of forming holes having a two-dimensional periodicity in a plane parallel to the first optical guide layer, in the first optical guide layer by etching; (d) supplying a gas containing a group-III material and a nitrogen source and performing growth to form recessed portions having a facet of a predetermined plane direction above openings of the holes, thereby closing the openings of the holes; and (e) of planarizing the recessed portions by mass transport, after the openings of the holes have been closed, wherein after said the planarizing, at least one side surface of the holes is a {10-10} facet.

Abstract: A two-dimensional photonic crystal surface emitting laser has, in a plate-shaped base body, a two-dimensional photonic crystal layer in which modified refractive index region pairs are periodically arranged and an active layer provided on one side of the base body, each of the modified refractive index region pairs including a first modified refractive index region and a second modified refractive index region having refractive indexes different from a refractive index of the base body, wherein an area of a planar shape of the first modified refractive index region is larger than or equal to an area of a planar shape of the second modified refractive index region, and a thickness of the first modified refractive index region is smaller than a thickness of the second modified refractive index region.

Abstract: A thermal emission source is provided that has a structure capable of suppressing deterioration of an optical assembly over time. The thermal emission source includes an optical assembly (1) having an optical structure in which a member made of a semiconductor has a refractive index distribution so as to resonate with light of a wavelength shorter than a wavelength that corresponds to an absorption edge corresponding to a band gap of the semiconductor. The optical assembly (1) includes a coating structure (30) with a coating material that differs from the semiconductor of refractive portions (10) and through which light of a wavelength included in a wavelength range from visible light to far infrared rays can be transmitted.

Abstract: A two-dimensional photonic crystal surface emitting laser has, in a plate-shaped base body, a two-dimensional photonic crystal layer in which modified refractive index region pairs are periodically arranged and an active layer provided on one side of the base body, each of the modified refractive index region pairs including a first modified refractive index region and a second modified refractive index region having refractive indexes different from a refractive index of the base body, wherein an area of a planar shape of the first modified refractive index region is larger than or equal to an area of a planar shape of the second modified refractive index region, and a thickness of the first modified refractive index region is smaller than a thickness of the second modified refractive index region.

Abstract: A thermal emission source capable of switching the intensity of light at a high response speed similarly to a photoelectric conversion element. A thermal emission source includes: a two-dimensional photonic crystal including a slab in which an n-layer made of an n-type semiconductor, a quantum well structure layer having a quantum well structure, and a p-layer made of a p-type semiconductor are stacked in the mentioned order in the thickness direction, wherein modified refractive index areas (air holes) whose refractive index differs from the refractive indices of the n-layer, the p-layer and the quantum well structure layer are cyclically arranged in the slab so as to resonate with a specific wavelength of light corresponding to a transition energy between the subbands in a quantum well in the quantum well structure layer; and a p-type electrode and an n-type electrode for applying, to the slab, a voltage which is negative on the side of the p-layer and positive on the side of the n-layer.

Abstract: A thermal emission source capable of switching the intensity of light at a high response speed similarly to a photoelectric conversion element. A thermal emission source includes: a two-dimensional photonic crystal including a slab in which an n-layer made of an n-type semiconductor, a quantum well structure layer having a quantum well structure, and a p-layer made of a p-type semiconductor are stacked in the mentioned order in the thickness direction, wherein modified refractive index areas (air holes) whose refractive index differs from the refractive indices of the n-layer, the p-layer and the quantum well structure layer are cyclically arranged in the slab so as to resonate with a specific wavelength of light corresponding to a transition energy between the subbands in a quantum well in the quantum well structure layer; and a p-type electrode and an n-type electrode for applying, to the slab, a voltage which is negative on the side of the p-layer and positive on the side of the n-layer.

Abstract: A thermal emission source that allows a wider range of material choices than those of conventional techniques, so that light having a desired peak wavelength can easily be obtained. A thermal emission source includes a thermo-optical converter composed of an optical structure in which a refractive index distribution is formed in a member made of an intrinsic semiconductor so as to resonate with light of a shorter wavelength than a wavelength corresponding to a bandgap of the intrinsic semiconductor. When heat is externally supplied to the thermo-optical converter, light having a spectrum in a band of shorter wavelengths than a cutoff wavelength is produced by interband absorption in the intrinsic semiconductor, and light of a resonant wavelength ?r in the wavelength band, the light causing resonance in the optical structure, is selectively intensified and emitted as thermal emission.