Integrated circuitry is fabricated from semiconductor layers formed on a substrate, which include at least one n-type layer, an inverted p-type modulation doped quantum well (mod-doped QW) structure, a non-inverted n-type mod-doped QW structure, and at least one p-type layer including a first P+-type layer formed below a second P-type layer. An etch operation exposes the second p-type layer. P-type ions are implanted into the exposed second p-type layer. A gate electrode of a n-channel HFET device is formed in contact with the p-type ion implanted region. Source and drain electrodes of the n-channel HFET device are formed in contact with n-type ion implanted regions formed in contact with the n-type mod-doped QW structure. P-channel HFET devices, complementary BICFET devices, stacked complementary HFET devices and circuits and/or logic gates based thereon, and a variety of optoelectronic devices and optical devices can also be formed as part of the integrated circuitry.

A two-dimensional photonic-crystal laser includes: a substrate made of an n-type semiconductor; a p-type cladding layer on an upper side of the substrate made of a p-type semiconductor; an active layer on an upper side of the cladding layer; a two-dimensional photonic-crystal layer on an upper side of the active layer including a plate-shaped base body made of an n-type semiconductor wherein modified refractive index areas whose refractive index differs from the base body are arranged; a first tunnel layer between the substrate and cladding layer made of an n-type semiconductor having a carrier density higher than the substrate's; a second tunnel layer between the first tunnel and cladding layers, made of a p-type semiconductor having a carrier density higher than the p-type semiconductor layer's; a first electrode on a lower side of or in the substrate; and a second electrode on an upper side of the two-dimensional photonic-crystal layer.

Methods for designing a mode-selective optical device including one or more optical interfaces defining an optical cavity include: defining a loss function within a simulation space encompassing the optical device, the loss function corresponding to an electromagnetic field having an operative wavelength within the optical device resulting from an interaction between an input electromagnetic field at the operative wavelength and the one or more optical interfaces of the optical device; defining an initial structure for each of the one or more optical interfaces, each initial structure being defined using a plurality of voxels; determining values for at least one structural parameter and/or at least one functional parameter of the one or more optical interfaces by solving Maxwell's equations; and defining a final structure of the one or more optical interfaces based on the values for the one or more structural and/or functional parameters.

A grating coupled laser (GCL) includes an active section and a passive section. The passive section is butt coupled to the active section to form a butt joint with the active section. The active section includes an active waveguide. The passive section includes a passive waveguide, a transmit grating coupler, and a top cladding. The passive waveguide is optically coupled end to end with the active waveguide and includes a first portion and a second portion. The first portion of the passive waveguide is positioned between the second portion of the passive waveguide and the active waveguide. The transmit grating coupler is optically coupled to the passive waveguide and includes grating teeth that extend upward from the second portion of the passive waveguide. The top cladding is positioned directly above the first portion of the passive waveguide and is absent directly above at least some of the transmit grating coupler.

A light emitting apparatus includes a laminated structure provided at a substrate and including a plurality of columnar sections. The plurality of columnar sections each includes a light emitting layer including a plurality of first well layers, a first semiconductor layer provided between the substrate and the light emitting layer and containing Ga and N, an optical confining layer provided between the first semiconductor layer and the light emitting layer and confining light in the light emitting layer, and a second well layer provided between the first semiconductor layer and the optical confining layer. The first well layers and the second well layer are made of InGaN. The optical confining layer includes an InGaN layer. The composition formula of the first well layers is In.sub.xGa.sub.1-xN. The composition formula of the InGaN layer of the optical confining layer is In.sub.yGa.sub.1-yN. The composition formula of the second well layer is In.sub.zGa.sub.1-zN. The parameters x, y, and z satisfy 0<y<z<x<1.

A light emitting apparatus includes a substrate and a laminated structure provided at a substrate surface of the substrate and including a plurality of columnar sections. The columnar sections each include a light emitting layer which has a first end facing the substrate and a second end facing away from the substrate. A first cross section of each of the columnar sections taken along the directions perpendicular to the lamination direction of the laminated structure includes the first end. A second cross section of each of the columnar sections taken along the directions perpendicular to the lamination direction is a cross section that is part of the light emitting layer and located at a position shifted from the first cross section toward the side away from the substrate in the lamination direction. In the plan view viewed in the lamination direction, the position of the center of the first cross section differs from the position of the center of the second cross section.

Some embodiments relate to a method for forming a vertical cavity surface emitting laser (VCSEL) structure. The method includes forming an optically active layer over a lower reflective layer and forming an upper reflector over the optically active layer. A first spacer is formed along sidewalls of the upper reflector. An oxidation process is performed with the first spacer in place to oxidize a peripheral region of the optically active layer. A first etch process is performed on the lower reflective layer and the oxidized peripheral region, thereby forming a lower reflector and an optically active region.

An optoelectronic device includes an off-cut III-V semiconductor substrate, a set of epitaxial layers formed on the off-cut III-V semiconductor substrate, and a horizontal cavity surface-emitting laser (HCSEL) having a laser resonant cavity formed in the set of epitaxial layers. The same or another optoelectronic device includes a semiconductor substrate; a laser, epitaxially grown on the semiconductor substrate and having a laser resonant cavity; a semiconductor device, epitaxially grown on the semiconductor substrate and separated from the laser by a single trench having a first vertical wall abutting the laser and a second vertical wall abutting the semiconductor device; and at least one coating on at least one of the first vertical wall or the second vertical wall. The laser resonant cavity of the laser has a horizontal portion parallel to the semiconductor substrate, and each of the first vertical wall and the second vertical wall is oriented perpendicular to the semiconductor substrate.

A surface-emitting laser including a cladding layer, an active region, a first grating, a plurality of second gratings, a first electrode, and a second electrode is provided. The active region is disposed on the cladding layer. The first grating is disposed on the active region. The second gratings are disposed on the active region and separately distributed among the first grating. A diffraction order of the first grating is different from a diffraction order of the second gratings. The first electrode is electrically connected to the cladding layer. The second electrode covers at least the first grating.

Provided is a laser device including a lower reflective layer, a laser cavity comprising an active layer disposed on the lower reflective layer, an upper reflective layer disposed on the laser cavity, and a blocking structure disposed between the laser cavity and the upper reflective layer, in which the blocking structure includes a first intermediate layer disposed on the laser cavity, a blocking layer disposed on the first intermediate layer and including a through-hole, and a second intermediate layer disposed on the blocking layer.