A topological bulk laser includes a topological photonic crystal (32) having an energy band inversion between dipole mode and quadrupole mode near the center of Brillouin zone and a trivial photonic crystal (31) not having band inversion for splicing to each other. The reflection and confinement of an optical field occurs at the interface; and the interface encloses to form a closed contour, thereby forming a laser cavity with an effective cavity feedback for lasing at the interior of the interface. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. At room temperature, the topological bulk laser can achieve low threshold, narrow linewidth, and a high side-mode suppression ratio, reduce the fabrication difficulty and costs, and improve heat dissipation and electrical injection efficiency, hence improving lifetime and stability of devices.

A light-emitting device includes: a substrate; first column portions provided at the substrate; a plurality of second column portions provided at the substrate and that surround the first column portions as viewed from a normal direction of the substrate; a first semiconductor layer coupled to the first column portions; an insulating layer covering the first semiconductor layer and the second column portions; and a wiring line electrically coupled to the first semiconductor layer. Each of the first column portions and each of the second column portions includes an n-type second semiconductor layer, a p-type third semiconductor layer, and a u-type fourth semiconductor layer. The fourth semiconductor layer at each of the first column portions is injected with current to emit light. The fourth semiconductor layer at each of the second column portions is not injected with current. The wiring line overlaps at least one of the second column portions.

A semiconductor laser device comprises an active layer having a main extension plane, a first cladding layer and a second cladding layer where the active layer is arranged between the first and second cladding layer in a direction perpendicular to the main extension plane, at least one first emission region and at least one second emission region arranged next to each other in a direction parallel to the main extension plane, a light-outcoupling surface parallel to the main extension direction and arranged on a side of the second cladding layer opposite to the active layer, and a photonic crystal layer arranged in the first cladding layer or in second cladding layer. The photonic crystal layer may include a first photonic crystal structure in the first emission region and a second photonic crystal structure in the second emission region where the first and the second photonic crystal structures are different.

A semiconductor laser device comprises an active layer having a main extension plane, a first cladding layer and a second cladding layer where the active layer is arranged between the first and second cladding layer in a direction perpendicular to the main extension plane, at least one first emission region and at least one second emission region arranged next to each other in a direction parallel to the main extension plane, a light-outcoupling surface parallel to the main extension direction and arranged on a side of the second cladding layer opposite to the active layer, and a photonic crystal layer arranged in the first cladding layer or in second cladding layer. The photonic crystal layer may include a first photonic crystal structure in the first emission region and a second photonic crystal structure in the second emission region where the first and the second photonic crystal structures are different.

A visible light source includes a substrate, a vertical-cavity surface-emitting laser including an active semiconductor region configured to emit infrared light and a first reflector configured to reflect the infrared light emitted by the active semiconductor region, a second reflector configured to reflect the infrared light and form a vertical cavity for the infrared light with the first reflector, and one or more micro-resonators configured to receive the infrared light and generate visible light in one or more colors using the infrared light through optical parametric oscillation. The visible light source also includes one or more output couplers configured to couple the visible light in one or more colors from the one or more micro-resonators into free space or into a photonic integrated circuit.

A visible light source includes a substrate, a vertical-cavity surface-emitting laser including an active semiconductor region configured to emit infrared light and a first reflector configured to reflect the infrared light emitted by the active semiconductor region, a second reflector configured to reflect the infrared light and form a vertical cavity for the infrared light with the first reflector, and one or more micro-resonators configured to receive the infrared light and generate visible light in one or more colors using the infrared light through optical parametric oscillation. The visible light source also includes one or more output couplers configured to couple the visible light in one or more colors from the one or more micro-resonators into free space or into a photonic integrated circuit.

A light-emitting device includes a laminate provided at a substrate, a first electrode provided on an opposite side of the laminate from the substrate, and a second electrode provided on an opposite side of the first electrode from the substrate. The laminate includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer. The first semiconductor layer is provided between the substrate and the light-emitting layer. The first electrode constitutes a plurality of column portions. The second electrode is coupled to the plurality of column portions. The first electrode is a transparent electrode formed of a metal oxide transmitting light generated at the light-emitting layer.

A surface-emitting laser element includes: a first guide layer including a photonic crystal layer that is formed on a c plane of a group-3 nitride semiconductor and includes air holes arranged with two-dimensional periodicity in a plane parallel to the photonic crystal layer, and an embedding layer that is formed on the photonic crystal layer and closes the air holes; an active layer formed on the first guide layer; and a second guide layer formed on the active layer, wherein an air hole set including at least a main air hole and a sub-air hole smaller in size than the main air hole is arranged at each square lattice point in the plane parallel to the photonic crystal layer, and wherein the main air hole has a regular-hexagonal prism shape, a long-hexagonal prism shape, or an elliptic cylindrical shape with a major axis parallel to a <11-20> axis.

A surface-emitting laser element includes: a first guide layer including a photonic crystal layer that is formed on a c plane of a group-3 nitride semiconductor and includes air holes arranged with two-dimensional periodicity in a plane parallel to the photonic crystal layer, and an embedding layer that is formed on the photonic crystal layer and closes the air holes; an active layer formed on the first guide layer; and a second guide layer formed on the active layer, wherein an air hole set including at least a main air hole and a sub-air hole smaller in size than the main air hole is arranged at each square lattice point in the plane parallel to the photonic crystal layer, and wherein the main air hole has a regular-hexagonal prism shape, a long-hexagonal prism shape, or an elliptic cylindrical shape with a major axis parallel to a <11-20> axis.

A surface-emitting semiconductor light-emitting device includes a semiconductor substrate; a first semiconductor layer on a front surface of the semiconductor substrate, an active layer on the first semiconductor layer; a photonic crystal layer on the active layer, a second semiconductor layer on the photonic crystal layer, a first electrode on the second semiconductor layer; and a second electrode on a back surface of the semiconductor substrate. The photonic crystal layer includes a plurality of protrusions arranged along an upper surface of the active layer. The second electrode includes a planar contact portion contacting the back surface of the semiconductor substrate, and at least one fine wire contact portion extending into a surface-emitting region in the back surface of the semiconductor substrate. The light radiated from the active layer is externally emitted from the surface-emitting region. The fine wire contact portion is arranged in the surface-emitting region with rotationally asymmetric.