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 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 nitride semiconductor laser device of one embodiment of the present disclosure includes a single-crystal substrate, a base layer, a sheet-shaped structure, a light emitting layer, and a resonator mirror. The single-crystal substrate extends in one direction. The base layer is provided on the single-crystal substrate and includes a nitride semiconductor. The sheet-shaped structure is provided on the base layer to stand in a direction perpendicular to the base layer. The sheet-shaped structure has an area of a side surface that is greater than an area of an upper surface. The side surface extends in a longitudinal direction of the single-crystal substrate. The sheet-shaped structure includes a nitride semiconductor. The light emitting layer is provided at least on the side surface of the sheet-shaped structure. The light emitting layer includes a nitride semiconductor. The resonator mirror is provided by a pair of end surfaces of the sheet-shaped structure that oppose each other in the longitudinal direction.

A light-emitting device is provided. An active layer is disposed on a substrate and between the first semiconductor layer and the second semiconductor layer. The first aluminum-containing semiconductor layer is disposed between the substrate and the first semiconductor layer, and a first aluminum composition ratio of the first aluminum-containing semiconductor layer is greater than that of the first semiconductor layer. The second aluminum-containing semiconductor layer is disposed between the first aluminum-containing semiconductor layer and the first semiconductor layer, and a second aluminum composition ratio of the second aluminum-containing semiconductor layer is greater than that of the first semiconductor layer. The stack structure is disposed between the first and second aluminum-containing semiconductor layers, and the stack structure includes first, second, and third indium-containing semiconductor layers stacked in sequence. The first, second, and third indium-containing semiconductor layers are made of In.sub.a1Al.sub.b1Ga.sub.1-a1-b1N (0<a1+b1<1), In.sub.a2Al.sub.b2Ga.sub.1-a2-b2N (0<a2+b2<1, and In.sub.a3Al.sub.b3Ga.sub.1-a3-b3N (0<a3+b3<1), respectively, and 0<a3≤a1<a2.

An optical semiconductor device includes a multi-quantum well layer including well layers and barrier layers alternately overlapping with each other, an optical confinement layer, and a guide layer interposed between the multi-quantum well layer and the optical confinement layer. Each barrier layer is an undoped layer and an outermost layer is one of the barrier layers. The optical confinement layer has a refractive index that is greater than that of the outermost layer and a band gap that is smaller than that of the outermost layer. The guide layer includes a first adjacent layer in contact with the outermost layer and the guide layer is thinner than the optical confinement layer. Each of the optical confinement layer and the guide layer is an n-type semiconductor layer. The first adjacent layer of the guide layer has a band gap that is larger than that of the optical confinement layer.

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.

In order to provide a QCL element operating in the near-infrared wavelength range, the present disclosure provides a quantum cascade laser element 1000 having a semiconductor superlattice structure (QCL structure 100) sandwiched between a pair of conductive sections 20 and 30. The semiconductor superlattice structure serves as an active region that emits electromagnetic waves. The active region has a plurality of unit structures 10U that are stacked on top of each other. Each unit structure includes four well layers 10W1-10W4 of a composition of Al.sub.xGa.sub.1-xN, separated from each other by barrier layers 10B1-10B5 of a composition of Al.sub.yGa.sub.1-yN with 0≤x<y≤1. Both of the conductive sections in the pair of conductive sections have a refractive index lower than that of the active region in which doped TCO inserted as a key role.

A semiconductor vertical light source includes upper and lower mirrors with an active region in between, an inner mode confinement region, and an outer current blocking region that includes a common epitaxial layer including an epitaxially regrown interface between the active region and upper mirror. A conducting channel including acceptors is in the inner mode confinement region. The current blocking region includes a first impurity doped region with donors between the epitaxially regrown interface and active region, and a second impurity doped region with acceptors between the first doped region and lower mirror. The outer current blocking region provides a PNPN current blocking region that includes the upper mirror or a p-type layer, first doped region, second doped region, and lower mirror or an n-type layer. The first and second impurity doped region force current flow into the conducting channel during normal operation of the light source.

A light emitting device includes: a substrate; a laminated structure that is provided on the substrate and that includes a plurality of columnar portions; and an electrode provided at an opposite side of the laminated structure from the substrate. The columnar portion includes a first semiconductor layer, a second semiconductor layer of a conductivity type different from that of the first semiconductor layer, and a light emitting layer located between the first semiconductor layer and the second semiconductor layer. The electrode is connected to the second semiconductor layers in the plurality of columnar portions, and includes a first electrode layer formed of a material that has a work function smaller than that of the second semiconductor layer, and a second electrode layer that is connected to the first electrode layer and that has a work function smaller than that of the first electrode layer. An interface between the first electrode layer and the second electrode layer has an uneven shape.

A method for making a laser diode with a distributed grating reflector (RT) in a planar section of a semiconductor laser with stabilized wavelength includes providing a diode formed by a substrate (S), a first cladding layer (CL1) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL1) and adapted to emit a radiation, and a second cladding layer (CL2) arranged on the active layer (A), said cladding layers (CL1, CL2) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer. The manufacturing method provides for creating, on a first portion (ZA) of the device, a waveguide (GO) for confinement of the optical radiation and, on the remaining portion (ZP) of the device, two different gratings for light reflection and confinement. The two gratings define two different zones (R1, R2), wherein the first zone (R1) includes a grating of low order and high duty cycle, and is intended for reflection, and the second zone (R2) includes a grating of the same order, or a grating of a higher order than the previous one, and low duty cycle, and is mainly intended for light confinement. The waveguide (GO) for confining the optical radiation is implemented through a lithography and a subsequent etching, whereas the grating (RT) requires a high-resolution lithography and a shallow etching starting from a planar zone.