Abstract: A solid state laser is disclosed wherein a semiconductor active layer is arranged in a Fabry-Perot cavity and the active layer is doped with a rare earth ion having a dominant emission wavelength. The proportion of elements for the compound active layer is chosen such that the bandgap corresponds to a wavelength which is longer than the emission wavelength of the rare earth ion. In the specific embodiment disclosed, the quarternary semiconductor compound is gallium indium arsenide phosphide and the rare earth ion is erbium.

Abstract: Semiconductor lasers having cleaved optically coupled cavities operating electrically isolated produce output of a single longitudinal mode. Wavelength tuning of the single longitudinal mode is possible.

Abstract: A structure having a sawtooth graded bandgap region between two layers having the same conductivity type is useful as a photodetector.

Abstract: Epitaxial layers of semiconductor materials such as, e.g., III-V and II-VI materials are deposited on a substrate under high-vacuum conditions. Molecules of a compound of a constituent of such material travel essentially line-of-sight towards the substrate admixed to a carrier gas such as, e.g., hydrogen. For III-V layers the use of compounds, such as, e.g., trimethyl- and triethylgallium, trimethyl- and triethylindium, triethylphosphine, and trimethylarsine is advantageous and economical in the manufacture of electronic and opto-electronic devices.

Abstract: A double active layer semiconductor laser having single longitudinal mode operation is described. The laser comprises first and second active layers which are separated from each other by an intermediate barrier layer but are optically coupled to each other so that, effectively, single mode operation results.

Abstract: A ridge waveguide laser with the ridge being grown through a stripe opened in an oxide layer covering one of the cladding layers is described. In one embodiment, the cladding layer is corrugated and the ridge waveguide laser is a distributed feedback laser.

Abstract: Semiconductor lasers having cleaved optically coupled cavities operating electrically isolated produce output of a single longitudinal mode. Wavelength tuning of the single longitudinal mode is possible.

Abstract: A method of selective area epitaxial growth using a scanning ion beam is described.

Abstract: A large optical cavity injection laser having a plurality of active layers within the large optical cavity. The active layers having a thickness great enough so that quantum effects are not significant.

Abstract: A photodetector having a graded bandgap region is an ultrahigh speed photodetector when operated at zero bias.

Abstract: A method of making a ridge waveguide laser with the ridge being grown through a stripe opened in an oxide layer covering one of the cladding layers is described. In one embodiment, the cladding layer is corrugated and the ridge waveguide laser is a distributed feedback laser.

Abstract: Frequency shift keying optical communications devices using a cleaved coupled cavity laser are described. The cleaved coupled cavity laser comprises first and second laser diode sections which are mutually optically coupled to each other and means for adjusting the refractive index of the first and second sections relative to each other. The cleaved coupled cavity laser is part of a light source which further comprises means for selecting at least one desired output frequency from a group of at least two output frequencies.

Abstract: A semiconductor laser having a graded index waveguide layer has low current thresholds.

Abstract: A multistage avalanche photodetector in which the ionization energy is provided by an energy band discontinuity is described. The photodetector provides low noise optical detection at low voltage.

Abstract: A lateral selective area liquid phase epitaxy method useful for the fabrication of, for example, a double barrier buried heterostructure laser, is described.

Abstract: Molecular beam epitaxy apparatus that permits a cryo-panel on which high vapor pressure material has condensed to be removed from the growth chamber to an outgassing chamber permits the high vapor pressure material, such as phosphorus, to be easily used in growing compound semiconductor materials is described. The apparatus has an evacuable first chamber with a plurality of effusion ovens and an evacuable second chamber with a valve connecting the chambers. The apparatus further comprises apparatus for moving a cryo-panel between the first and second chambers and apparatus for heating the cryo-panel in the second chamber.

Abstract: A double barrier double heterostructure laser is described in which relatively narrow beam divergence is obtained by the presence of wide bandgap, with respect to the cladding layers and barrier layers intermediate the active and cladding layers.

Abstract: A region of saturable absorption is produced in semiconductor lasers by proton bombardment and results in subpicosecond optical pulses.

Abstract: An oxide layer (16') is formed on a GaAs body (14) by epitaxially growing a layer (12) of Al.sub.x Ga.sub.1-x As layer on a major surface (18) of the body and then thermally oxidizing the Al.sub.x Ga.sub.1-x As layer for a time period effective to convert it to an oxide. The oxidizing process is essentially self-terminating at the major surface 18. The application of this process to the fabrication of MOS capacitors and IGFETs is described.

Abstract: A light transducer (10) is described in which a semi-insulating, single crystal body (12) of light-absorbing semiconductor material has a pair of spaced-apart epitaxial zones (14, 16) of opposite conductivity type integrally and electrically coupled to a surface (18) of the body. The zones, which may be mesas epitaxially grown on the surface or regions diffused or ion-implanted in the surface, are positioned so that radiation (20) absorbed between them generates photocarriers which are able to diffuse and/or drift to the zones. Also described is an array of transducers in which the photovoltages developed across a plurality of pairs of zones are added in series.