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.

The present invention provides a semiconductor laser device for improving temperature characteristics of waveguide structures and realizing stable light emitting patterns and high output, and a method for making the same. The semiconductor laser device (1) comprises: an n-type clad layer (5) laminated on a substrate (2); an active layer (6) laminated on the n-type clad layer (5); a p-type clad layer (7) laminated on the active layer (6); and a plurality of waveguide structures (8) formed on the p-type clad layer (7) and having a ridge of a horn shape in top view. In this configuration, a divider (29) is formed between adjacent waveguide structures (8), and the divider (29) comprises: a groove (30) dividing the active layer (6); and a heat dissipation material (34) filled in the groove (30) and having a thermal conductivity higher than a thermal conductivity of a semiconductor layer (4).

Provided is a butt-jointed (BJ) semiconductor integrated optical device having a high manufacturing yield. A semiconductor integrated optical device, which is configured such that, on a semiconductor substrate, a first semiconductor optical element including an active layer and a second semiconductor optical element including a waveguide layer are butt-jointed to each other with their optical axes being aligned with each other, includes: a semiconductor regrowth layer including at least one of a diffraction grating layer or an etching stop layer, which is formed by one epitaxial growth across an entire surface above the active layer and the waveguide layer; and a cladding layer formed above the semiconductor regrowth layer.

A vertical cavity surface emitting laser includes an active area, an inner trench, an outer trench, and a first implantation region. The active area includes a first mirror, an active region, a second mirror, and an etch stop layer. The first mirror is formed over a substrate. The active region is formed over the first mirror. The second mirror is formed over the active region. The etch stop layer with an aperture is formed between the active region and the second mirror. The inner trench surrounds the active area in a top view. The outer trench if formed beside the inner trench. The first implantation region is formed below the inner trench.

A semiconductor laser in a ridge waveguide structure includes: a semiconductor substrate; a lower cladding layer which is formed on the semiconductor substrate; an active layer and a semiconductor layer which are in parallel on the lower cladding layer and are connected with each other; a first upper cladding layer locally aligned above the active layer; a second upper cladding layer locally aligned above the semiconductor layer; and a third upper cladding layer locally aligned above the active layer to confine light which is guided in the active layer, wherein the semiconductor layer has a band gap which is larger than that of the active layer. According to this constitution, an optical semiconductor device with high reliability in which the ridge waveguide structure whose manufacturing is relatively easy is applied, and current diffusion and electrical crosstalk between lasers in the ridge waveguide structure are suppressed is enabled.

An edge-emitting semiconductor laser includes a semiconductor structure having a waveguide layer with an active layer, the waveguide layer extending in a longitudinal direction between first and second side facets of the semiconductor structure, the semiconductor structure has a tapering region adjacent to the first side facet, a thickness of the waveguide layer in the tapering region increases longitudinally, the waveguide layer is arranged between first and second cladding layers, a thickness of the second cladding layer in the tapering region of the semiconductor structure increases longitudinally, the tapering region includes first and second subregions, the first subregion is arranged closer to the first side facet than the second subregion, thickness of the waveguide layer increases longitudinally in the first subregion, thickness of the waveguide layer is constant in the longitudinal direction in the second subregion, and thickness of the second cladding layer increases longitudinally in the second subregion.

A reflector structure for a tunable laser and a tunable laser. A super structure grating is used as a reflector structure, and a suspended structure is formed around a region in which the super structure grating is located, to implement, using the suspended structure, thermal isolation around the region in which the super structure grating is located, and increase thermal resistance, such that less heat is lost, and heat is concentrated in the region in which the super structure grating is located, thereby improving thermal tuning efficiency of the reflector structure. Moreover, lateral support structures are disposed on two sides of the suspended structure, to provide a mechanical support for the suspended structure. In addition, regions in the super structure grating that correspond to any two lateral support structures on a same side of the suspended structure fall at different locations in a spatial period of the super structure grating.

A method of fabricating vertical cavity surface emitting laser, comprising: providing a first substrate formed with a dielectric DBR and a first bonding layer, and a second substrate formed with a etch-stop layer, a heavily doped layer, an active region, a current-confinement layer, and an arsenide DBR firstly, then sticking a third substrate on the arsenide DBR, then removing the second substrate and the etch-stop layer, next bonding the heavily doped layer to the dielectric DBR, next removing the third substrate, finally forming a p-type electrode contact and an n-type electrode contact.

Several VCSEL devices for long wavelength applications in wavelength range of 1200-1600 nm are described. These devices include an active region between a semiconductor DBR on a GaAs wafer and a dielectric DBR regrown on the active region. The active region includes multi-quantum layers (MQLs) confined between the active n-InP and p-InAlAs layers and a tunnel junction layer above the MQLs. The semiconductor DBR is fused to the bottom of the active region by a wafer bonding process. The design simplifies integrating the reflectors and the active region stack by having only one wafer bonding followed by regrowth of the other layers including the dielectric DBR. An air gap is fabricated either in an n-InP layer of the active region or in an air gap spacer layer on top of the semiconductor DBR. The air gap enhances optical confinement of the VCSEL. The air gap may also contain a grating.

A laser includes a distributed Bragg minor and is configured to emit monochromatic light radiation along a longitudinal direction. The laser has layers, stacked along a first transverse direction normal to the longitudinal direction and made of III-V materials, including an active region configured to emit the radiation. The mirror is formed by periodic lateral corrugations which extend mainly along the longitudinal direction and having a dimension along a second transverse direction normal to the longitudinal direction. The lateral corrugations of the Bragg minor extend from a top surface of the waveguide pattern along the first transverse direction on a height strictly less than the depth, at which the active region is located starting from the top surface, such that a portion of lateral flanks of the waveguide is free of any lateral corrugations at the active region.