A light emitting device includes a wiring substrate, a light emitting element array that includes a first side surface and a second side surface facing each other, and a third side surface and a fourth side surface connecting the first side surface and the second side surface to each other and facing each other, the light emitting element array being provided on the wiring substrate, a driving element that is provided on the wiring substrate on the first side surface side and drives the light emitting element array, a first circuit element and a second circuit element that are provided on the wiring substrate on the second side surface side to be arranged in a direction along the second side surface, and a wiring member that is provided on the third side surface side and the fourth side surface side and extends from a top electrode of the light emitting element array toward an outside of the light emitting element array.

A semiconductor laser element includes a first emitter having a first active layer and a first guide layer, and a second emitter having a second active layer and a second guide layer. A thickness of the first emitter is different from a thickness of the second emitter so that an average value of an index DB1 and an index DB2 represented by equations (1) and (2) is 5% or less,

[Equation 1]

DB1=?|F.sub.1(?)?F.sub.01(?)|d?(1)

[Equation 2]

DB2=?|F.sub.2(?)?F.sub.02(?)|d?(2)

F.sub.1(?) is a far field pattern when it is assumed that only the first emitter is present, and F.sub.2(?) is a far field pattern when it is assumed that only the second emitter is present. F.sub.01(?) is a far field pattern of one of two modes corresponding to a fundamental mode of the light emitted from the first and second emitters, and F.sub.02(?) is a far field pattern of the other one.

[Object] To provide a laser device that has a concave mirror structure and exhibits excellent optical characteristics, a laser device array, and a method of producing the laser device.

[Solving Means] A laser device according to the present technology includes: a first light-reflecting layer; a second light-reflecting layer; and a stacked body. The stacked body includes an active layer, a lens being provided on a first surface on a side of the first light-reflecting layer. The lens has a lens shape protruding toward a side of the first light-reflecting layer with a first direction as a longitudinal direction and a second direction as a lateral direction, a central portion of the lens in the first direction having a first width that is the shortest width along the second direction, a non-central portion of the lens in the first direction having a second width that is the largest width along the second direction, the lens having a shape in which a height thereof is uniform or the central portion is higher than an end portion, a radius of curvature of an apex of the lens in the second direction being uniform. The first light-reflecting layer is stacked on the first surface to form a concave mirror having a concave surface shape on the lens.

To provide a two-dimensional photonic crystal surface emitting laser capable of improving characteristics of light to be emitted, in particular, optical output power. The two-dimensional photonic crystal surface emitting laser 10X includes: a two-dimensional photonic crystal 123 including a plate-shaped base member 121 and modified refractive index regions 122 where the modified refractive index regions 122 have a refractive index different from that of the plate-shaped base member 121 and are two-dimensionally and periodically arranged in the base member; an active layer 11 provided on one side of the two-dimensional photonic crystal 123; and a first electrode 15A and a second electrode 16 provided sandwiching the two-dimensional photonic crystal 123 and the active layer 11 for supplying current to the active layer 11, where the second electrode 16 covers a region equal to or wider than the first electrode 15A, wherein the first electrode 15A is formed so as to supply the current to the active layer 11 with a different density depending on the in-plane position on the first electrode 15A.

A semiconductor device comprising a nominally or exactly or equivalent orientation silicon substrate on which is grown directly a <100 nm thick nucleation layer (NL) of a III-V compound semiconductor, other than GaP, followed by a buffer layer of the same compound, formed directly on the NL, optionally followed by further III-V semiconductor layers, followed by at least one layer containing III-V compound semiconductor quantum dots, optionally followed by further III-V semiconductor layers. The NL reduces the formation and propagation of defects from the interface with the silicon, and the resilience of quantum dot structures to dislocations enables lasers and other semiconductor devices of improved performance to be realized by direct epitaxy on nominally or exactly or equivalent orientation silicon.

In a semiconductor laser device, a n-type cladding layer, a multi-quantum well active layer, and a p-type cladding layer are sequentially laminated on an n-type substrate, and a stripe structure is provided on this semiconductor laminated section. The n-type cladding layer has a first n-type cladding layer configured of Al.sub.x1Ga.sub.1-x1As (0.4<x11), and a second n-type cladding layer configured of (Al.sub.x2Ga.sub.1-x2).sub.1-y2In.sub.y2P (0x21, 0.45y20.55). The p-type cladding layer is configured of (Al.sub.x3Ga.sub.1-x3).sub.1-y3In.sub.y3P (0x31, 0.45y30.55). The width of the stripe structure is 10 m or more, and the refractive index with respect to the laser oscillation wavelength of the first n-type cladding layer is less than or equal to the refractive index with respect to the laser oscillation wavelength of the second n-type cladding layer.

The methods of manufacture of GeSiSn heterojunction bipolar transistors, which include light emitting transistors and transistor lasers and photo-transistors and their related structures are described herein. Other embodiments are also disclosed herein.

The present embodiment relates to a single semiconductor light-emitting element including a plurality of light-emitting portions each of which is capable of generating light of a desired beam projection pattern and a method for manufacturing the semiconductor light-emitting element. In the semiconductor light-emitting element, an active layer and a phase modulation layer are formed on a common substrate layer, and the phase modulation layer includes at least a plurality of phase modulation regions arranged along the common substrate layer. The plurality of phase modulation regions are obtained by separating the phase modulation layer into a plurality of places after manufacturing the phase modulation layer, and as a result, the semiconductor light-emitting element provided with a plurality of light-emitting portions that have been accurately aligned can be obtained through a simple manufacturing process as compared with the related art.

To increase the maximum operating temperature of quantum cascade lasers of a terahertz region, a quantum cascade laser element 1000 according to the present invention has a semiconductor superlattice structure sandwiched between a pair of electrodes, the semiconductor superlattice structure has an active region 100 that emits electromagnetic waves of a frequency in a THz region under an external voltage applied through the pair of electrodes for operation, and the active region 100 has plural unit structures 10U, each of which is repeatedly layered over one another. Each of the unit structures 10U has a double quantum well structure formed of a first well layer 10W1 and a second well layer 10W2 separated from each other by a barrier layer, the first well layer 10W1 and the second well layer 10W2 have compositions different from each other, and when the external voltage is not being applied, potential energy for electrons in the second well layer 10W2 is lower than that in the first well layer 10W1.

A method of forming a pair of edge-emitting lasers is provided. The method includes forming a mesa from a substrate, forming a cover layer on the substrate around the mesa, and forming a first barrier layer on each of opposite sidewalls of the mesa. The method further includes forming a quantum well layer on each of the barrier layers, forming a second barrier layer on each of the quantum well layers, and forming a cladding layer on each of the second barrier layers.