Abstract: A surface-emitting laser includes an active layer; multiple reflectors sandwiching the active layer; and an electrode pair connected to a power supply, through which a current is injected into the active layer. The surface-emitting laser emits at least one laser beam during a current injection period when the current injected into the active layer through the electrode pair during the current injection period is a first current and emits at least one laser beam during a current decrease period when the current injected into the active layer through the electrode pair during the current injection period is a second current exceeding the first current. The current decrease period is after the current injection period. The current injected into the active layer during the current decrease period is lower than the current injected into the active layer during the current injection period.

Abstract: A surface-emitting laser array includes a substrate and a sub-arrays disposed on the substrate, the sub-arrays including a surface-emitting laser devices electrically connected to each other in parallel to emit light through the substrate, each of the surface-emitting laser devices having a light-emitting point and including a first semi-conducting layer of first conductivity. The laser array further includes a second semi-conducting layer of second conductivity, and a resonator disposed between the first semi-conducting layer and the second semi-conducting layer. The sub-arrays adjacent to each other include an electrode to electrically connect the first semi-conducting layer in the surface-emitting laser devices included in one of the sub-arrays and the second semi-conducting layer.

Abstract: An optical device includes a light source provided with a plurality of surface-emitting laser elements to emit a laser beam, a scanner to scan the laser beam emitted from the light source, and an optical system disposed in an optical path between the light source and the scanner and to guide the laser beam to the scanner. The optical system includes a first optical element to control a divergence angle of the laser beam emitted from the light source and a second optical element to concentrate the laser beam that has passed through the first optical element onto a to-be-scanned surface of the scanner.

Abstract: A distance measuring apparatus includes a light source to emit light beams, an optical scanner to scan the light beams output from the light source over a predetermined range, a light receiver to receive reflected light obtained as a result of the light beams being reflected by a target object, and to output detection signals, and a control circuit to measure a distance to the target object based on the detection signals. The light source including a plurality of light-emitting device groups that are arranged in a scan direction of a scan performed by the optical scanner, and the control circuit being to make the plurality of light-emitting device groups emit light at respective different timings in a single scan, and to measure the distance to the target object based on a sum of the detection signals.

Abstract: A surface emitting laser module includes a base substrate, a surface emitting laser substrate mounted on the base substrate, the surface emitting laser substrate including a surface emitting laser element, and the surface emitting laser substrate having a first face facing the base substrate and a second face facing away from the base substrate, and an optical member facing the second face and including an optical element configured to receive light emitted from the second face of the surface emitting laser element. The surface emitting laser element includes a first semiconductor layer, a second semiconductor layer, a first electrode provided on the first face and connected to the first semiconductor layer, and a second electrode provided on the first face and connected to the second semiconductor layer. The base substrate includes a third electrode connected to the first electrode and a fourth electrode connected to the second electrode.

Abstract: Laser devices include a light source that emits a laser beam, an optical system that concentrates the laser beam emitted from the light source, an optical window through which the laser beam exited from the optical system passes, a housing that accommodates the optical system, and an optical window holding member fixed to the housing. The optical window holding member holds the optical window. In the first laser device, the optical window has a face or a protruding face through which the laser beam passes. When the optical window has the face, the face is flush with an edge of the optical window holding member and a film is formed on the face. When the optical window has the protruding face, the protruding face protrudes with reference to the edge of the optical window holding member and a film is formed on the protruding face.

Abstract: An ignition device configured to ignite a fuel included in an air-fuel mixture supplied to a main combustion chamber of an internal combustion engine. The ignition device includes a partition member that forms a precombustion chamber that encloses an ignition point of a fuel. The partition member has a plurality of communicating holes communicating between the main combustion chamber and the precombustion chamber. The ignition device further includes a first interference member that protrudes inward from an inner surface of the partition member.

Abstract: An optical device includes a light source provided with a plurality of surface-emitting laser elements to emit a laser beam, a scanner to scan the laser beam emitted from the light source, and an optical system disposed in an optical path between the light source and the scanner and to guide the laser beam to the scanner. The optical system includes a first optical element to control a divergence angle of the laser beam emitted from the light source and a second optical element to concentrate the laser beam that has passed through the first optical element onto a to-be-scanned surface of the scanner.

Abstract: A surface emitting laser includes a first reflecting mirror; a second reflecting mirror; an active region between the first reflecting mirror and the second reflecting mirror. The first reflecting mirror and the second reflecting mirror each include a plurality of low refractive-index layers having a first refractive index; and a plurality of high refractive-index layers having a second refractive index higher than the first refractive index. The plurality of low refractive-index layers and the plurality of high refractive-index layers are alternated one after another. The plurality of high refractive-index layers of the first reflecting mirror includes a first layer; and a second layer having a higher thermal diffusion property in an in-plane direction than the first layer.

Abstract: A surface-emitting laser array includes a plurality of surface-emitting laser elements, a plurality of optical elements, and a light shielding member. The plurality of surface-emitting laser elements are arranged on a first surface of a substrate and configured to emit light in a direction crossing the first surface. The plurality of optical elements are arranged on a second surface opposite to the first surface of the substrate to correspond to the surface-emitting laser elements and configured to change a radiation angle of the light. The light shielding member is arranged in a region between the optical elements on the second surface of the substrate.

Abstract: A laser device includes a light source device including a semiconductor laser; and a laser cavity irradiated with light from the light source device and including a saturable absorber. A beam waist diameter r of the light that irradiates the laser cavity and an initial transmittance T0 of the saturable absorber satisfy a relationship of 7.75×T04?7.77×T03+3.13×T02+0.16×T0+0.74?r?2.62×T0+0.675.

Abstract: A laser device and an internal combustion engine. The laser device includes a light source configured to emit light, an optical system configured to concentrate the light emitted from the light source, a housing configured to accommodate the optical system, and a window disposed to the housing, to which the light passed through the optical system is incident. The window includes an optical window through which the light exited from the optical system passes, an optical window holding member configured to hold the optical window, a joint configured to join the optical window to the optical window holding member, and a protective layer disposed to a face of the joint. The internal combustion engine includes the laser device according to claim, and a combustion chamber configured to burn fuel to produce inflammable gas. In the internal combustion engine, the fuel is ignited by the laser device.

Abstract: A surface-emitting laser array includes a plurality of light emitting parts. Each light emitting part includes a reflection mirror including aluminum gallium arsenide (AlxGa(1-x)As) where x is greater than 0.95 but less than or equal to 1; an active layer; and an electrode surrounding an emission region, from which laser light is emitted, the electrode covering a region between adjacent light emitting parts in the plurality of light emitting parts.

Abstract: A distance measuring apparatus includes a light source to emit light beams, an optical scanner to scan the light beams output from the light source over a predetermined range, a light receiver to receive reflected light obtained as a result of the light beams being reflected by a target object, and to output detection signals, and a control circuit to measure a distance to the target object based on the detection signals. The light source including a plurality of light-emitting device groups that are arranged in a scan direction of a scan performed by the optical scanner, and the control circuit being to make the plurality of light-emitting device groups emit light at respective different timings in a single scan, and to measure the distance to the target object based on a sum of the detection signals.

Abstract: An ignition device configured to ignite a fuel included in an air-fuel mixture supplied to a main combustion chamber of an internal combustion engine. The ignition device includes a partition member that forms a precombustion chamber that encloses an ignition point of a fuel. The partition member has a plurality of communicating holes communicating between the main combustion chamber and the precombustion chamber. The ignition device further includes a first interference member that protrudes inward from an inner surface of the partition member.

Abstract: A laser device includes a light source device including a semiconductor laser; and a laser cavity irradiated with light from the light source device and including a saturable absorber. A beam waist diameter r of the light that irradiates the laser cavity and an initial transmittance T0 of the saturable absorber satisfy a relationship of 7.75×T04?7.77×T03+3.13×T02+0.16×T0+0.74?r?2.62×T0+0.675.

Abstract: A laser device and an internal combustion engine. The laser device includes a light source configured to emit light, an optical system configured to concentrate the light emitted from the light source, a housing configured to accommodate the optical system, and a window disposed to the housing, to which the light passed through the optical system is incident. The window includes an optical window through which the light exited from the optical system passes, an optical window holding member configured to hold the optical window, a joint configured to join the optical window to the optical window holding member, and a protective layer disposed to a face of the joint. The internal combustion engine includes the laser device according to claim, and a combustion chamber configured to burn fuel to produce inflammable gas. In the internal combustion engine, the fuel is ignited by the laser device.

Abstract: A surface-emitting laser includes an active layer on which a spacer layer is disposed, and a reflection mirror disposed on the spacer layer, including a current constriction layer that is a selectively-oxidized layer having been selectively oxidized. The current constriction layer is disposed at a position of a node of a standing-wave of an electric field of light oscillated at the active layer and is disposed away from an interface between the spacer layer and the reflection mirror by an optical distance of one-fourth of an oscillation wavelength at the active layer. The selectively-oxidized layer is made of AlGaAs. The reflection mirror includes at least one AlGaInP layer contacting the selectively-oxidized layer.

Abstract: Laser devices include a light source that emits a laser beam, an optical system that concentrates the laser beam emitted from the light source, an optical window through which the laser beam exited from the optical system passes, a housing that accommodates the optical system, and an optical window holding member fixed to the housing. The optical window holding member holds the optical window. In the first laser device, the optical window has a face or a protruding face through which the laser beam passes. When the optical window has the face, the face is flush with an edge of the optical window holding member and a film is formed on the face. When the optical window has the protruding face, the protruding face protrudes with reference to the edge of the optical window holding member and a film is formed on the protruding face.

Abstract: A surface-emitting laser apparatus includes a surface-emitting laser substrate; a microlens substrate; and an adhesion agent. The surface-emitting laser substrate includes a semiconductor substrate; and a surface-emitting laser and plural first adhesion fixing regions formed on a first face of the semiconductor substrate. The microlens substrate includes a microlens configured to receive light emitted by the surface-emitting laser; plural pier portions protruding toward a side of the first face of the semiconductor substrate; and plural second adhesion fixing regions, formed at positions corresponding to the first adhesion fixing regions on surfaces of the pier portions. The adhesive agent causes the first adhesion fixing regions and the second adhesion fixing regions to adhere to each other. A restoring force acts on the adhesive agent in a case where the adhesive agent is melted.