Abstract: A thermal radiation light source includes a laminated body including m quantum layers laminated where m is an integer of 2 or more, including an n-layer and a p-layer sandwiching the quantum layers from both sides in the laminating direction, the n-layer made of an n-type semiconductor and the p-layer made of a p-type semiconductor; a voltage applying unit for the m quantum layers is directly or indirectly connected to the n-layer and p-layer sandwiching each layer applying a voltage for moving to the n-layers or p-layers a charge; a voltage switching unit switches ON/OFF of application of the voltage to the m quantum layers; and a photonic crystal portion disposed in the laminated body or adjacent to the laminated body, so that lights of m wavelengths resonate, the lights of the m wavelengths generated in the m quantum layers corresponding to transition energy between subbands in the quantum layer.

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 control circuit in this laser equipment drives a drive circuit of a photonic crystal laser element under a predetermined condition. It was found that a wavelength width of a laser beam to be output from the photonic crystal laser element is dependent on a standardized drive current k and a pulse width T, and had a predetermined relationship with these. By meeting this condition, a laser beam with a plurality of wavelengths can be controlled and output.

Abstract: A laser module includes: a photonic crystal surface-emitting laser element; a collimating lens array for producing a parallel optical beam; a condenser lens for condensing the optical beam; and an optical fiber which receives the optical beam on one end and transmits the optical beam to the outside. In the collimating lens array, an aperture portion corresponding to a collimating lens allows passage of the optical beam with an energy of not less than 94.0% and not more than 99.5% with respect to 100% of the energy of the optical beam incident on the collimating lens array.

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 two-dimensional photonic crystal surface emitting laser capable of improving characteristics of light to be emitted, particularly optical output , which includes: a two-dimensional photonic crystal including a plate-shaped base member and modified refractive index regions where the modified refractive index regions have a refractive index different from that of the plate-shaped base member and are two-dimensionally and periodically arranged in the base member; an active layer provided on one side of the two-dimensional photonic crystal; and a first electrode and a second electrode provided sandwiching the two-dimensional photonic crystal and the active layer for supplying current to the active layer, where the second electrode covers a region equal to or wider than the first electrode, wherein the first electrode is formed so as to supply the current to the active layer with a different density depending on the in-plane position on the first electrode.

Abstract: A control circuit in this laser equipment drives a drive circuit of a photonic crystal laser element under a predetermined condition. It was found that a wavelength width of a laser beam to be output from the photonic crystal laser element is dependent on a standardized drive current k and a pulse width T, and had a predetermined relationship with these. By meeting this condition, a laser beam with a plurality of wavelengths can be controlled and output.

Abstract: A surface emitting laser element capable of emitting a main beam and a sub-beam, and a monitoring light detection element capable of detecting a light intensity of the sub-beam are included, the surface emitting laser element is a PCSEL, the main beam and the sub-beam are emitted in an upward direction of the surface emitting laser element and are inclined to each other at a predetermined angle, and respective changes in a peak light intensity of the main beam and a peak light intensity of the sub-beam with respect to a value of a driving current of the surface emitting laser element are correlated with each other. Therefore, if an output of the monitoring light detection element indicating the peak light intensity of the sub-beam is used, the peak light intensity of the main beam can be estimated.

Abstract: In a laser device, a different refractive index region 6B of a photonic crystal layer is arranged at a lattice point position of a square lattice. In the case where a plane shape of the different refractive index regions 6B is a nearly isosceles right triangle, two sides forming a right angle extend along longitudinal and horizontal lateral lines of the square lattice. A direction parallel to or vertical to an oblique side of the triangle and a direction of polarization in the periodic polarization inversion structure of a nonlinear optical crystal NL are the same.

Abstract: In a laser device, a different refractive index region 6B of a photonic crystal layer is arranged at a lattice point position of a square lattice. In the case where a plane shape of the different refractive index regions 6B is a nearly isosceles right triangle, two sides forming a right angle extend along longitudinal and horizontal lateral lines of the square lattice. A direction parallel to or vertical to an oblique side of the triangle and a direction of polarization in the periodic polarization inversion structure of a nonlinear optical crystal NL are the same.

Abstract: A two-dimensional photonic crystal surface emitting laser has a laminated structure including: a two-dimensional photonic crystal (2DPC) layer in which refractive index distribution is formed by two-dimensionally arranging air holes in a plate-shaped base member; and an active layer for generating light with wavelength ?L by receiving an injection of electric current. The two-dimensional photonic crystal surface emitting laser emits a laser beam in the direction of an inclination angle ? from normal to the 2DPC 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 semiconductor laser element is realized with high beam quality (index M2<1). A diffraction grating 6ba of a diffraction grating layer 6 extends along a principal surface 2a and is provided on a p-side surface 6a of the diffraction grating layer 6; the refractive index of the diffraction grating layer 6 periodically varies in directions extending along the principal surface 2a, in the diffraction grating 6ba; the diffraction grating 6ba has a plurality of holes 6b; the plurality of holes 6b are provided in the p-side surface 6a and arranged in translational symmetry along a square lattice R3; the plurality of holes 6b each have the same size and shape; each hole 6b corresponds to a lattice point of the diffraction grating 6ba and is of a triangular prism shape; a shape of a bottom face 6c of the hole 6b is an approximate right triangle.

Abstract: A surface emitting laser element capable of emitting a main beam and a sub-beam, and a monitoring light detection element capable of detecting a light intensity of the sub-beam are included, the surface emitting laser element is a PCSEL, the main beam and the sub-beam are emitted in an upward direction of the surface emitting laser element and are inclined to each other at a predetermined angle, and respective changes in a peak light intensity of the main beam and a peak light intensity of the sub-beam with respect to a value of a driving current of the surface emitting laser element are correlated with each other. Therefore, if an output of the monitoring light detection element indicating the peak light intensity of the sub-beam is used, the peak light intensity of the main beam can be estimated.

Abstract: A two-dimensional photonic crystal surface emitting laser has a laminated structure including: a two-dimensional photonic crystal (2DPC) layer in which refractive index distribution is formed by two-dimensionally arranging air holes in a plate-shaped base member; and an active layer for generating light with wavelength ?L by receiving an injection of electric current. The two-dimensional photonic crystal surface emitting laser emits a laser beam in the direction of an inclination angle ? from normal to the 2DPC layer.

Abstract: A two-dimensional photonic crystal surface emitting laser has a laminated structure including: a two-dimensional photonic crystal (2DPC) layer in which refractive index distribution is formed by two-dimensionally arranging air holes in a plate-shaped base member; and an active layer for generating light with wavelength ?L by receiving an injection of electric current. The two-dimensional photonic crystal surface emitting laser emits a laser beam in the direction of an inclination angle ? from normal to the 2DPC layer.

Abstract: A two-dimensional photonic crystal surface emitting laser has a laminated structure including: a two-dimensional photonic crystal (2DPC) layer in which refractive index distribution is formed by two-dimensionally arranging air holes in a plate-shaped base member; and an active layer for generating light with wavelength ?L by receiving an injection of electric current. The two-dimensional photonic crystal surface emitting laser emits a laser beam in the direction of an inclination angle ? from normal to the 2DPC layer.

Abstract: A solar cell (1) of the present invention includes a photoelectric conversion layer (2) and a photonic crystal provided inside the photoelectric conversion layer (2) in order to have a photonic band gap. The photonic crystal has defects (31) in order to provide a defect level in the photonic band gap. QV which is a Q value representing a magnitude of a resonance effect yielded by coupling between the photonic crystal and an outside is substantially equal to Q? which is a Q value representing a magnitude of a resonance effect yielded by a medium of the photoelectric conversion layer (2).

Abstract: An object to provide a photonic crystal capable of resonating light at more resonant frequencies within a particular frequency range. A plurality of photonic crystal structure formation bodies each including a plate-like member in which cyclic refractive index distribution is formed are provided so as to be spaced apart from each other in the thickness direction of the plate-like member, and the respective refractive index distributions of the plurality of photonic crystal structure formation bodies are set such that: at least one of the plurality of photonic crystal structure formation bodies resonates with light having at least two frequencies within the frequency range; and the two frequencies are different from resonant frequencies of at least one of the other photonic crystal structure formation bodies.

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.