A semiconductor optical device includes a substrate of a first conductivity type; an optical confinement layer of the first conductivity type, which is arranged above the substrate of the first conductivity type; a multi quantum well layer, which is arranged above the optical confinement layer of the first conductivity type, and comprises a plurality of well layers and a plurality of barrier layers; an optical confinement layer of a second conductivity type, which is arranged on the multi quantum well layer; and a PL stabilization layer, which is arranged between the substrate of the first conductivity type and the multi quantum well layer. The PL stabilization layer having a thickness that is half a thickness of the multi quantum well layer or more, and having a composition wavelength that is shorter than a composition wavelength of the plurality of well layers of the multi quantum well layer.

An embodiment relates to a surface emitting laser device and a light emitting device including the same. The surface emitting laser device according to the embodiment may include a first reflective layer; an active layer disposed on the first reflective layer; an active region disposed on the active layer and having an aperture and an insulation region disposed around the aperture; and a second reflective layer disposed on the active region. The second reflective layer may include a core reflective layer disposed in a position vertically corresponding to the aperture. The embodiment may include a cladding insulation layer disposed around the core reflective layer. The horizontal cross-section of the aperture may be different from the horizontal cross-section of the core reflective layer.

A vertical cavity light-emitting element includes a substrate, a first multilayer film reflecting mirror, a semiconductor structure layer, an electrode, an electrode layer, and a second multilayer film reflecting mirror. The first multilayer film reflecting mirror is formed on the substrate. The semiconductor structure layer includes a nitride semiconductor. The nitride semiconductor includes a first semiconductor layer that is formed on the first multilayer film reflecting mirror and is a first conductivity type, a second semiconductor layer that is formed on the first semiconductor layer and is the first conductivity type, a light-emitting layer that is formed on the second semiconductor layer and is configured to expose a region including an outer edge of a top surface of the second semiconductor layer, and a third semiconductor layer that is formed on the light-emitting layer and is a second conductivity type opposite to the first conductivity type. The electrode is formed on the top surface of the second semiconductor layer. The electrode layer is electrically in contact with the third semiconductor layer in one region of a top surface of the third semiconductor layer. The second multilayer film reflecting mirror constitutes a resonator with the first multilayer film reflecting mirror. The second semiconductor layer has a larger resistance than the first semiconductor layer.

A semiconductor laser is provided that includes a semiconductor layer sequence and electrical contact surfaces. The semiconductor layer sequence includes a waveguide with an active zone. Furthermore, the semiconductor layer sequence includes a first and a second cladding layer, between which the waveguide is located. At least one oblique facet is formed on the semiconductor layer sequence, which has an angle of 45° to a resonator axis with a tolerance of at most 10°. This facet forms a reflection surface towards the first cladding layer for laser radiation generated during operation. A maximum thickness of the first cladding layer is between 0.5 M/n and 10 M/n at least in a radiation passage region, wherein n is the average refractive index of the first cladding layer and M is the vacuum wavelength of maximum intensity of the laser radiation.

A semiconductor device having a GeSiSn base region combined with an emitter region and a collector region can be used to fabricate a bipolar transistor or a heterojunction bipolar transistor. The GeSiSn base region can be compositionally graded or latticed matched or strained to GaAs. The GeSiSn base region can be wafer bonded to a GaN or SiC collector region.

A light emitting device includes: a substrate including a main surface; a first projection positioned on the main surface, the first projection including an upper surface and first and second lateral surfaces, wherein the first lateral surface of the first projection comprises a first reflective part, and the second lateral surface of the first projection comprises a second reflective part; a first laser element configured to irradiate laser light to the first reflective part; a second laser element configured to irradiate laser light to the second reflective part; and a first optical member fixed to the upper surface of the first projection, wherein the first optical member comprises a first lens part positioned above the first reflective part, and a second lens part positioned above the second reflective part.

Techniques for efficient alignment of a semiconductor laser in a Photonic Integrated Circuit (PIC) are disclosed. In some embodiments, a photonic integrated circuit (PIC) may include a semiconductor laser that includes a laser mating surface, and a substrate that includes a substrate mating surface. A shape of the laser mating surface and a shape of the substrate mating surface may be configured to align the semiconductor laser with the substrate in three dimensions.

A laser diode (1) includes an AlN single crystal substrate (11), an n-type cladding layer (12) formed on the substrate and including a nitride semiconductor layer having n-type conductivity, a light-emitting layer (14) formed on the n-type cladding layer and including one or more quantum wells, a p-type cladding layer (20) formed on the light-emitting layer and including a nitride semiconductor layer having p-type conductivity, and a p-type contact layer (18) formed on the p-type cladding layer and including a nitride semiconductor that includes GaN. The p-type cladding layer includes a p-type longitudinal conduction layer (16) that includes Al.sub.sGa.sub.1−sN (0.3≤s≤1), has a composition gradient such that the Al composition s decreases with increased distance from the substrate, and has a film thickness of less than 0.5 μm, and a p-type transverse conduction layer (17) that includes Al.sub.tGa.sub.1−tN (0<t≤1).

A semiconductor laser is formed to include a current blocking layer that is positioned below the active region of the device and used to minimize current spreading beyond the defined dimensions of an output beam's optical mode. When used in conjunction with other current-confining structures typically disposed above the active region (e.g., ridge waveguide, electrical isolation, oxide aperture), the inclusion of the lower current blocking layer improves the efficiency of the device. The current blocking layer may be used in edge-emitting devices or vertical cavity surface-emitting devices, and also functions to improve mode shaping and reduction of facet deterioration by directing current flow away from the facets.

A semiconductor optical amplifier integrated laser includes a semiconductor laser oscillator portion that oscillates laser light having a wavelength included in a gain band and a semiconductor optical amplifier portion that amplifies laser light output from the semiconductor laser oscillator portion. The semiconductor laser oscillator portion and the semiconductor optical amplifier portion have one common p-i-n structure, the common p-i-n structure includes an active layer, a cladding layer provided apart from the active layer, and a common functional layer formed in the cladding layer, and the common functional layer includes a first portion that reflects light having a wavelength within the gain band in the semiconductor laser oscillator portion and a second portion that transmits light having a wavelength within the gain band in the semiconductor optical amplifier portion.