Embodiments of the present disclosure are directed towards a laser device with a stepped graded index separate confinement heterostructure (SCH), in accordance with some embodiments. One embodiment includes a substrate area, and an active region adjacent to the substrate area. The active region includes an SCH layer, which comprises a first portion and a second portion adjacent to the first portion. A composition of the first portion is graded to provide a first conduction band energy increase over a distance from multiple quantum wells (MQW) to a p-side of a laser device junction. A composition of the second portion is graded to provide a second conduction band energy increase over the MQW to the p-side distance. The first conduction band energy increase is different than the second conduction band energy increase. Other embodiments may be described and/or claimed.

The invention relates to a quantum cascade laser (300) comprising a gain region (102) inserted between two optical confinement layers (104.sub.1, 104.sub.2), said gain region (102) having an electron input into the gain region (102) and an electron output from said gain region (102) characterized in that said laser comprises a hole-blocking area (304) on the side of said electron output.

System and method for increasing VCSEL power by using multiple gain layers 10, separated by insulated layers 12, bounded on top and bottom by DBR mirrors 11, connected in parallel through electrodes embedded within, resulting in a modified VCSEL system of higher power, lower resistive loss, higher device speed, and higher beam quality.

There is provided a semiconductor laser including: a first mirror layer; a second mirror layer; an active layer; a current confinement layer; a first region including a plurality of first oxidized layers; and a second region including a plurality of second oxidized layers, in which, in a plan view, the laminated body includes a first part including the first region and the second region, a second part including the first region and the second region, and a third part disposed between the first part and the second part and resonating light generated in the active layer, the third part includes a fourth part including the first region and the second region and having a first groove, a fifth part including the first region and the second region and having a second groove, and a sixth part disposed between the fourth part and the fifth part and sandwiched between the first part and the second part, in a plan view.

A semiconductor laser (2) includes an n-type semiconductor substrate (1), a stack of an n-type cladding layer (4), an active layer (5), and a p-type cladding layer (6) successively stacked on the n-type semiconductor substrate (1). An optical waveguide (3) includes a non-impurity-doped core layer (9) provided on a light output side of the semiconductor laser (2) on the n-type semiconductor substrate (1) and having a larger forbidden band width than the active layer (5), and a cladding layer (10) provided on the core layer (9) and having a lower carrier concentration than the p-type cladding layer (6). The semiconductor laser (2) includes a carrier injection region (X1), and a non-carrier-injection region (X2) provided between the carrier injection region (X1) and the optical waveguide (3).

A semiconductor vertical light source includes upper and lower minors 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 minor. 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 minor. The outer current blocking region provides a PNPN current blocking region that includes the upper minor or a p-type layer, first doped region, second doped region, and lower minor 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 laser diode vertical epitaxial structure, comprising a transverse waveguide comprising an active layer between an n-type semiconductor layer and a p-type semiconductor layer wherein the transverse waveguide is bounded by a lower index n-cladding layer on an n-side of the transverse waveguide and a lower index p-cladding layer on a p-side of the transverse waveguide, a lateral waveguide that is orthogonal to the transverse waveguide, wherein the lateral waveguide is bounded in a longitudinal direction at a first end by a facet coated with a high reflector (HR) coating and at a second end by a facet coated with a partial reflector (PR) coating and a higher order mode suppression layer (HOMSL) disposed adjacent to at least one lateral side of the lateral waveguide and that extends in a longitudinal direction.

A vertical cavity surface emitting laser (VCSEL) has first and second electrical contacts, and an optical resonator. The optical resonator has first and second distributed Bragg reflectors (DBRs), an active layer, a distributed heterojunction bipolar phototransistor (DHBP), and an optical guide. The DHBP has a collector layer, light sensitive layer; a base layer; and an emitter layer. There is an optical coupling between the active layer and the DHBP for providing an active carrier confinement by the DHBP. The optical guide guides an optical mode within the optical resonator during operation. The optical guide is outside a current flow which can be provided by the first and second electrical contacts during operation of the VCSEL. The optical guide is outside a layer sequence between the first and second electrical contacts in the vertical direction of the VCSEL. The optical guide has an oxide aperture arranged in the second DBR.

A light emitting device is provided that makes it possible to reduce absorption of light by an electrode. The light emitting device includes a substrate, and a laminated structure provided to the substrate, wherein the laminated structure includes a first semiconductor layer, a second semiconductor layer different in conductivity type from the first semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, the first semiconductor layer is disposed between the substrate and the active layer, a recessed part is disposed at an opposite side to the substrate side of the laminated structure, the recessed part is provided with a low refractive-index part lower in refractive index than the second semiconductor layer, a depth of the recessed part is no larger than a distance between a surface at an opposite side to the substrate side of the laminated structure and the active layer, and an electrode is disposed at an opposite side to the substrate side of the laminated structure.

A monolithic integrated semiconductor random laser composed of a gain region and random feedback region, comprising: a substrate, a lower confinement layer on the substrate, an active layer on the lower confinement layer, an upper confinement layer on the active layer, a strip-shaped waveguide layer longitudinally made in middle of the upper confinement layer, a P.sup.+ electrode layer divided into two segments by an isolation groove and made on the waveguide layer, and an N.sup.+ electrode layer on a back face of the lower confinement layer. The two segments of the P.sup.+ electrode layer correspond respectively to the gain region and the random feedback region. The random feedback region uses a doped waveguide to randomly feed back light emitted and amplified by the gain region. As a result, random laser is emitted. Frequency and intensity of laser emitted by semiconductor laser are random, and a monolithic integration structure is used, making semiconductor laser be light, small, stable in performance, and strong in integration.