Abstract: A lateral injection VCSEL comprises upper and lower mirrors forming a cavity resonator, an active region disposed in the resonator, high conductivity upper and lower contact layers located on opposite sides of the active region, upper and lower electrodes disposed on the upper and lower contact layers, respectively, and on laterally opposite sides of the upper mirror, and a current guide structure including an apertured high resistivity layer for constraining current to flow in a relatively narrow channel through the active region, characterized in that a portion of the lower contact layer that extends under the top electrode has relatively high resistivity. This feature of our invention serves two purposes. First, it suppresses current flow in parallel paths and, therefore, tends to make the current density distribution in the aperture more favorable for the fundamental mode. Second, it reduces parasitic capacitance.

Abstract: Disclosed are a method of making GaAs-based enhancement-type MOS-FETs, and articles (e.g., GaAs-based ICs) that comprise such a MOS-FET. The MOS-FETs are planar devices, without etched recess or epitaxial re-growth, with gate oxide that is primarily Ga2O3, and with low midgap interface state density (e.g., at most 1×1011 cm−2 eV−1 at 20° C.). The method involves ion implantation, implant activation in an As-containing atmosphere, surface reconstruction, and in situ deposition of the gate oxide. In preferred embodiments, no processing step subsequent to gate oxide formation is carried out above 300° C. in air, or above about 700° C. in UHV. The method makes possible fabrication of planar enhancement-type MOS-FETs having excellent characteristics, and also makes possible fabrication of complementary MOS-FETs, as well as ICs comprising MOS-FETs and MES-FETs.

Abstract: A VCSEL comprises separate current and optical guides that provide unique forms of drive current and transverse mode confinement, respectively. In one embodiment, the optical guide comprises an intracavity high refractive index mesa disposed transverse to the cavity resonator axis and a multi-layered dielectric (i.e., non-epitaxial) mirror overlaying the mesa. In another embodiment, the current guide comprises an annular first electrode which laterally surrounds the mesa but has an inside diameter which is greater than that of an ion-implantation-defined current aperture. The current guide causes current to flow laterally from the first electrode along a first path segment which is essentially perpendicular to the resonator axis, then vertically from the first segment along a second path segment essentially parallel to that axis, and finally through the current aperture and the active region to a second electrode.

Abstract: A VCSEL comprises a pair of multi-layered mirrors forming an optical cavity resonator having its axis perpendicular to the layers of the mirrors, an active region disposed within the resonator, and a current guide for directing pumping current through an aperture to generate stimulated emission of radiation which propagates along the resonator axis. A portion of the radiation forms an output signal which emerges through at least one of the mirrors. The current guide includes a lateral injection structure disposed between one of the mirrors and the current aperture. The lateral injection structure comprises at least one relatively thin, highly doped semiconductor layer, each of the highly doped layer(s) being located at a node of the standing wave of the intracavity radiation, at least one lower doped semiconductor layer disposed adjacent each of the highly doped layers (e.g.

Abstract: A high quality oxide layer has been formed on a GaN surface by a method that involves preparation of the GaN such that the surface is essentially atomically clean and essentially atomically ordered, and that further involves exposing the surface to evaporant from a GGG (gallium gadolinium garnet) evaporation source. MOS structures comprising the GaN/oxide combination have shown low leakage current, as well as charge accumulation and depletion.

Abstract: The inventive III/V semiconductor lasers comprise mode-shaping layers disposed in the upper and lower cladding regions, respectively, and having larger refractive index than the adjoining cladding material. Incorporation of the mode-shaping layers can significantly spread the mode structure of the laser, with attendant reduction of beam spreading. Preferred embodiments are Al-free III/V semiconductor lasers. Especially preferred are such lasers that do not have quaternary III/V semiconductor material between active region and substrate, for improved heat removal.

Abstract: In a method of making a GaAs-based semiconductor laser, a fully processed wafer is cleaved, typically in the ambient atmosphere, into laser bars, the laser bars are loaded into an evacuable deposition chamber (preferably an ECR CVD chamber) and exposed to a H.sub.2 S plasma. Following the exposure, the cleavage facets are coated in the chamber with a protective dielectric (preferably silicon nitride) layer. The method can be practiced with high through-put, and can yield lasers (e.g., 980 nm pump lasers for optical fiber amplifiers) capable of operation at high power.