Abstract: A novel InP-based semiconductor laser comprises an unpatterned active region that is essentially co-extensive with the substrate of the laser, an electron stopper layer, and a separate confinement heterostructure (SCH) layer that has a portion of thickness greater than the thickness of the remainder of the SCH layer. The difference in thickness serves to provide lateral guiding of the laser mode. A patterned current blocking layer is disposed on the SCH layer, with a window in the blocking layer defining the region of increased thickness of the SCH layer. The inventive laser is readily manufacturable and can have improved properties.

Abstract: A process for manufacturing selectively doped heterostructure field-effect transistors (SDHTs), a desired wafer structure for SDHT fabrication and a method for isolating SDHTs on the wafer are disclosed herein. The wafer has epitaxial layers grown on a substrate. The layers are: a buffer layer of GaAs, a first spacer layer of AlGaAs, a donor layer of AlGaAs, a second spacer layer of AlGaAs, a first cap layer of GaAs, an etch-stop layer of AlGaAs and a second cap layer of GaAs. A protective layer of AlGaAs may then be grown on the second cap layer to protect the second cap layer from contamination or damage. Also a superlattice may first be grown on the substrate.This invention was made with Government support under contract No. F29601-87-R-0202 awarded by the Defense Advanced Research Projects Agency, and under contract No. F33615-84-C-1570 awarded by the Air Force Wright Aeronautical Laboratories. The Government has certain rights in this invention.

Abstract: The specification describes an improved form of heterostructure laser, termed a "Rib-Loc" laser. It is an easily fabricated device with desirable electrical and optical properties. The Rib-Loc is simple to fabricate because a single, self-aligned rib provides ohmic contact, current confinement and lateral waveguiding. A deeply etched P-cladding layer outside the rib provides the positive index change needed for an index-guided laser. The large optical cavity increases the maximum power output and reduces the aspect ratio of the beam.

Abstract: In LPE boat-slider apparatus the boat, which carries the melts, is made of lower thermal conductivity material than the slider, which carries the substrate. Illustratively, the boat comprises sapphire and the slider comprises graphite. A confined-melt geometry is also described in which another slider, used to skim off thin portions of the melt, is also made of the lower thermal conductivity material.