Abstract: A double heterostructure laser having a pair of opposite-conductivity-type, wide bandgap cladding layers separated by a narrower bandgap active region is characterized in that the active region includes a low-loss waveguide layer and contiguous therewith a narrower bandgap active layer in the form of a narrow strip which extends along the longitudinal (resonator) axis of the laser. Suitable lateral current confinement means, such as reversed biased p-n junctions, are provided to constrain pumping current to flow in a narrow channel through the active layer. Lasers of this type exhibit relatively high pulsed power outputs (e.g., 400 mW), linear L-I characteristics, stable fundamental transverse mode and single longitudinal mode oscillation. In another embodiment the surfaces of the waveguide layer adjacent the active layer are provided with distributed feedback gratings.

Abstract: A semiconductor barrier Josephson junction device (10) comprises a semiconductor body (12) having a pair of parallel noncoplanar major surfaces (14, 16) which are joined along parallel edges (18, 20) by an oblique surface (22) which forms an acute angle with the major surfaces. Superconductive electrodes (24, 26) on the major surfaces extend near to the parallel edges and thereby define the tunneling barrier as the semiconductor region which extends along the oblique surface. Also described is an array of such junctions connected in series.

Abstract: Parallel channels are separated by ridges formed in a semiconductor body in such a way that each channel is wider at its base than at its top. Molecular beam epitaxy is used to deposit semiconductor layers on the ridges and in the channels. Because each channel is narrower at its top than at its base, the configuration is essentially self-masking. That is, the layers in the channel are physically separate from those on the ridges, as would be metallic contacts deposited on the layers. This technique is employed in the fabrication of a plurality of self-aligned, stripe geometry, mesa double heterostructure junction lasers.

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: Described is a method for fabricating a stripe geometry double heterostructure (DH) junction laser in which lateral current confinement is acheived by pairs of laterally spaced, reverse-biased p-n junctions. A mesa is formed on an n-GaAs substrate, for example, and a layer of p-AlGaAs is then grown by LPE so that nucleation does not occur on the top of the mesa. Laterally spaced zones of p-AlGaAs are thus formed on either side of the mesa. An n-p-p or n-n-p DH is then grown so that the interface between the p-AlGaAs layers and the first n-layer of the DH forms a pair of laterally spaced p-n junctions separated by the mesa. When the light-emitting p-n junction in the DH active region is forward biased, the air of spaced junctions are reverse biased so that pumping current is constrained to flow through the active region in a narrow channel to the mesa.

Abstract: A double heterostructure laser having a pair of opposite-conductivity-type, wide bandgap cladding layers separated by a narrower bandgap active region is characterized in that the active region includes a low-loss waveguide layer and contiguous therewith a narrower bandgap active layer in the form of a narrow strip which extends along the longitudinal (resonator) axis of the laser. Suitable lateral current confinement means, such as reversed biased p-n junctions, are provided to constrain pumping current to flow in a narrow channel through the active layer. Lasers of this type exhibit relatively high pulsed power outputs (e.g., 400 mW), linear L-I characteristics, stable fundamental transverse mode and single longitudinal mode oscillation. In another embodiment the surfaces of the waveguide layer adjacent the active layer are provided with distributed feedback gratings.

Abstract: Described is a stripe geometry double heterostructure (DH) junction laser in which lateral current confinement is achieved by pairs of laterally spaced, reverse-biased p-n junctions. A mesa is formed on an n-GaAs substrate, for example, and a layer of p-AlGaAs is then grown by LPE so that nucleation does not occur on the top of the mesa. Laterally spaced zones of p-AlGaAs are thus formed on either side of the mesa. An n-p-p or n-n-p DH is then grown so that the interface between the p-AlGaAs layers and the first n-layer of the DH forms a pair of laterally spaced p-n junctions separated by the mesa. When the light-emitting p-n junction in the DH active region is forward biased, the pair of spaced junctions are reverse biased so that pumping current is constrained to flow through the active region in a narrow channel to the mesa. Further lateral current confinement is achieved by forming on the upper DH surface a second pair of reverse biased p-n junctions separated by a window in alignment with the mesa.

Abstract: Parallel channels are separated by ridges formed in a semiconductor body in such a way that each channel is wider at its base than at its top. Molecular beam epitaxy is used to deposit semiconductor layers on the ridges and in the channels. Because each channel is narrower at its top than at its base, the configuration is essentially self-masking. That is, the layers in the channel are physically separate from those on the ridges, as would be metallic contacts deposited on the layers. This technique is employed in the fabrication of a plurality of self-aligned, stripe geometry, mesa double heterostructure junction lasers.

Abstract: An article and method for fabricating one and two dimensional arrays of superconducting and normal junctions by depositing metal films on photoresist gratings. In one mode superconducting Josephson junction arrays of the Dayem bridge type are fabricated by scratching a groove across the grating with a sharp diamond point.