Abstract: A semiconductor optical amplifier includes: a substrate; a light source unit formed on the substrate; and an optical amplification part that amplifies light propagating in a predetermined direction from the light source unit and emits the amplified light in an emission direction intersecting with the substrate surface. The optical amplification part includes a conductive region extending in the predetermined direction along the substrate surface from the light source unit, and a nonconductive region formed around the conductive region. The conductive region includes a first region extending from the light source unit and having a predetermined width as seen from a direction perpendicular to the substrate surface, and a second region connected to the first region and having a width widened relative to the predetermined width of the first region, the second region being configured to expand the propagation light in a direction intersecting with the predetermined direction.

Abstract: A semiconductor optical amplifier includes a conductive region that is provided on a substrate and allows light transmission, and a nonconductive region that is provided around the conductive region and prohibits light transmission. The conductive region includes a first region including a light-coupling portion to which light from an external light-source unit is coupled, and a second region having a narrower width than the first region and connected to the first region through a connecting portion, the second region including a light-amplifying portion amplifying the light from the light-coupling portion by propagating the light in a predetermined propagating direction along a surface of the substrate, the light-amplifying portion outputting the amplified light in a direction intersecting the surface of the substrate.

Abstract: A semiconductor light emitter includes a substrate, a semiconductor multilayer structure including a light emission unit that emits light in an oblique direction with respect to the substrate, a base on which the substrate is disposed, a holding member that holds the substrate at an angle set in advance with respect to the base, a temperature control unit disposed parallel to the substrate to adjust a temperature of the substrate, and a shaping optical system held against the substrate to shape a luminous flux emitted from the semiconductor multilayer structure.

Abstract: A semiconductor optical amplifier includes: a substrate; a light source unit that is formed on the substrate; and an optical amplification unit that includes a conductive region extending, from the light source unit, in a predetermined direction along a surface of the substrate, and a nonconductive region around the conductive region. The optical amplification unit amplifies propagation light that propagates, from the light source unit, in the predetermined direction as slow light, and emits the propagation light that is amplified in an emission direction that intersects with the surface. The maximum optical power of the propagation light is larger than the maximum optical power in a vertical oscillation mode.

Abstract: A semiconductor optical amplifier includes: a light source part that is formed on a substrate, the substrate including a substrate surface; and an optical amplification part that amplifies propagation light propagating in a predetermined direction from the light source part and that emits the propagation light amplified in an emission direction intersecting with the substrate surface, the optical amplification part including a conductive region extending in the predetermined direction from the light source part along the substrate surface and a non-conductive region formed on a periphery of the conductive region, the conductive region including a reflection part that reflects the propagation light in a direction intersecting with the predetermined direction when viewed from a direction vertical to the substrate surface.

Abstract: A light emitting element array includes a single semiconductor substrate, a plurality of semiconductor elements, which are formed on the single semiconductor substrate, and each of the semiconductor elements including a first distributed Bragg-reflector, an active layer formed over the first distributed Bragg-reflector, and a second distributed Bragg-reflector formed over the active layer. The array includes an electrode pad formed over the second distributed Bragg-reflector and a wiring formed at least partly over the second distributed Bragg-reflector and extending from the electrode pad toward the semiconductor elements. The semiconductor elements include a first semiconductor element, configured to emit laser light, and a second semiconductor element configured not to emit laser light and disposed at a position which is shorter distance along the wiring from the electrode pad than a distance along the wiring from the electrode pad to a position of the first semiconductor element.

Abstract: An optical semiconductor element includes: a semiconductor substrate that is semi-insulating; a columnar body that is formed on a front surface-side of the semiconductor substrate and configured to emit or receive light from the front surface-side; a front surface-side electrode that is connected to the columnar body; a back surface-side electrode formed on a back surface-side of the semiconductor substrate; and an electrically conductive member that is formed to penetrate through the semiconductor substrate to connect the front surface-electrode and the back surface-side electrode, and has a protruding portion protruding on the front surface-side of the semiconductor substrate.

Abstract: A semiconductor optical amplifier includes: a substrate; a light source unit formed on the substrate; and an optical amplification part that amplifies light propagating in a predetermined direction from the light source unit and emits the amplified light in an emission direction intersecting with the substrate surface. The optical amplification part includes a conductive region extending in the predetermined direction along the substrate surface from the light source unit, and a nonconductive region formed around the conductive region. The conductive region includes a first region extending from the light source unit and having a predetermined width as seen from a direction perpendicular to the substrate surface, and a second region connected to the first region and having a width widened relative to the predetermined width of the first region, the second region being configured to expand the propagation light in a direction intersecting with the predetermined direction.

Abstract: A semiconductor optical amplifier includes: a substrate; a light source unit that is formed on the substrate; and an optical amplification unit that includes a conductive region extending, from the light source unit, in a predetermined direction along a surface of the substrate, and a nonconductive region around the conductive region. The optical amplification unit amplifies propagation light that propagates, from the light source unit, in the predetermined direction as slow light, and emits the propagation light that is amplified in an emission direction that intersects with the surface. The maximum optical power of the propagation light is larger than the maximum optical power in a vertical oscillation mode.

Abstract: A semiconductor optical amplifier includes a conductive region that is provided on a substrate and allows light transmission, and a nonconductive region that is provided around the conductive region and prohibits light transmission. The conductive region includes a first region including a light-coupling portion to which light from an external light-source unit is coupled, and a second region having a narrower width than the first region and connected to the first region through a connecting portion, the second region including a light-amplifying portion amplifying the light from the light-coupling portion by propagating the light in a predetermined propagating direction along a surface of the substrate, the light-amplifying portion outputting the amplified light in a direction intersecting the surface of the substrate.

Abstract: A light emitting element array includes a single semiconductor substrate, a plurality of semiconductor elements, which are formed on the single semiconductor substrate, and each of the semiconductor elements including a first distributed Bragg-reflector, an active layer formed over the first distributed Bragg-reflector, and a second distributed Bragg-reflector formed over the active layer. The array includes an electrode pad formed over the second distributed Bragg-reflector and a wiring formed at least partly over the second distributed Bragg-reflector and extending from the electrode pad toward the semiconductor elements. The semiconductor elements include a first semiconductor element, configured to emit laser light, and a second semiconductor element configured not to emit laser light and disposed at a position which is shorter distance along the wiring from the electrode pad than a distance along the wiring from the electrode pad to a position of the first semiconductor element.

Abstract: A semiconductor optical amplifier includes: a light source part that is formed on a substrate, the substrate including a substrate surface; and an optical amplification part that amplifies propagation light propagating in a predetermined direction from the light source part and that emits the propagation light amplified in an emission direction intersecting with the substrate surface, the optical amplification part including a conductive region extending in the predetermined direction from the light source part along the substrate surface and a non-conductive region formed on a periphery of the conductive region, the conductive region including a reflection part that reflects the propagation light in a direction intersecting with the predetermined direction when viewed from a direction vertical to the substrate surface.

Abstract: An optical transmission device includes a first light emitting element, a second light emitting element, and a detection unit. The first light emitting element is configured to emit light. The second light emitting element is configured to emit light. The second light emitting element is connected in parallel with the first light emitting element and is configured to deteriorate earlier than the first light emitting element. The detection unit is configured to detect whether the second light emitting element is deteriorated.

Abstract: A light emitting element array includes plural light emitting elements connected in parallel to each other by a wiring connected to a terminal that supplies a current. Each of the light emitting elements is disposed at a position of a predetermined path length along a path of the current flowing from the terminal through the wiring. The plural light emitting elements include, in a mixed form, one or more first light emitting elements each having a non-shielded light emission aperture and one or more second light emitting elements each having a shielded light emission aperture. At least one of the first light emitting elements is disposed at a position of the longest path length. At least one of the second light emitting elements is disposed at a position of the shortest path length.

Abstract: A light emitting element includes: a semiconductor stack structure that includes a light emitting part, and a light receiving part that receives light propagating in a lateral direction through a semiconductor layer from the light emitting part, wherein the light emitting part and the light receiving part share a quantum layer; and a light reflection layer that covers ? or more of a lateral surface of the quantum layer in the light receiving part.

Abstract: A light emitting element array includes plural semiconductor stacking structures and a light screening portion. The plural semiconductor stacking structures each include a light emitting portion and a light receiving portion that receives light propagated in a lateral direction via a semiconductor layer from the light emitting portion. The light screening portion is provided between the plural semiconductor stacking structures to screen light directed from the light emitting portion of one of the semiconductor stacking structures to the light receiving portion of another semiconductor stacking structure.

Abstract: A light emitting element includes: a light emitting part that is formed on a front surface side of a semi-insulating substrate; and a light receiving part that is formed on the front surface side, that shares a semiconductor layer with the light emitting part, and that receives light propagating in a lateral direction through the semiconductor layer from the light emitting part, wherein anode electrodes and cathode electrodes of the light emitting part and the light receiving part are formed on the front surface side in a state in which the anode electrodes are separated from each other and the cathode electrodes are separated from each other.

Abstract: A light emitting element array includes plural light emitting elements connected in parallel to each other by a wiring connected to a terminal configured to supply a current. The number of light emitting elements which have the shortest path length among path lengths on the wiring from the terminal to the respective light emitting elements along a path of the current is one.

Abstract: A light emitting apparatus includes: a semiconductor layer including a light emitting region that generates modulation light modulated with a first signal, and a feedback region that is configured so that a feedback mode to feed back a part of light generated in the light emitting region to the light emitting region and a monitor mode to monitor a light amount of the light generated in the light emitting region are switchable; and a controller, wherein when the modulation light is generated in the light emitting region, the controller sets the feedback region to the feedback mode, and the controller switches the feedback region to the monitor mode during at least a part of a period in which there is no first signal.

Abstract: A light emitting element array includes plural semiconductor stacked structures each including a light emitting unit that is formed on a substrate, and a light amplification unit that extends from the light emitting unit along a substrate surface of the substrate to have a length in an extension direction which is longer than that of the light emitting unit, amplifies light propagating in the extension direction from the light emitting unit, and emits the amplified light from a light emission portion formed along the extension direction, wherein the plural semiconductor stacked structures are arranged such that the extension directions of the respective light amplification units are substantially parallel to each other.