Abstract: A micro-electromechanical optical switch assembly is provided for an optical network. The switch assembly includes arrays of input and output optical fibers and optical components for selecting light paths that connect any selected pair of input and output fibers. The optical components include optical switching elements, such as torsionally supported micromechanical mirrors that are electrostatically actuated to rotate to direct the light beam along the desired light path. The mirrors are bulk micromachined into a semiconductor wafer, preserving their optical qualities, and formed into a chip mated to a cover. The package incorporates alignment elements to ensure correct position and orientation of the optical components in the package.

Abstract: Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material such as III-V and particularly AIGaAs/GaAs material are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enabled device registration for LED bars and arrays to be maintained.

Abstract: A micro-electromechanical optical switch assembly is provided for an optical network. The switch assembly includes arrays of input and output optical fibers and optical components for selecting light paths that connect any selected pair of input and output fibers. The optical components include optical switching elements, such as torsionally supported micromechanical mirrors that are electrostatically actuated to rotate to direct the light beam along the desired light path. The mirrors are bulk micromachined into a semiconductor wafer, preserving their optical qualities, and formed into a chip mated to a cover. The package incorporates alignment elements to ensure correct position and orientation of the optical components in the package.

Abstract: Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material, such as III-V, and particularly AlGaAs/CaAs material, are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enable device registration for LED bars and arrays to be maintained.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material, such as III-V, and particularly AlGaAs/GaAs material, are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enable device registration for LED bars and arrays to be maintained.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material, such as III-V, and particularly AlGaAs/GaAs material, are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enable device registration for LED bars and arrays to be maintained.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline mateGOVERNMENT SUPPORTWork described herein was supported by the U.S. Air Force.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed which is employed in the construction of tandem solar cells. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is then separated and used to form a tandem solar cell while the substrate can be reused to form additional sheets.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is separated, and the substrate can optionally be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A three-dimensional optical waveguide is disclosed. This waveguide comprises a single crystal semiconductor layer grown upon an insulator which has an index of refraction lower than the semiconductor. The semiconductor layer has a thickness which provides confinement of light propagating in the semiconductor layer in the vertical direction. An effective larger index of refraction over a cross-sectional region of the semiconductor layer provides confinement of light in the lateral direction. This lateral confinement is achieved by side walls in the semiconductor layer which extend toward, but fall short of, the insulator layer.

Abstract: A method for fabricating three-dimensional optical waveguides is disclosed. In this method, a single crystal semiconductor layer is grown upon an insulator which has an index of refraction lower than the semiconductor. The semiconductor layer is deposited to a thickness which provides confinement of light propagating in the semiconductor layer in the vertical direction. An effective larger index of refraction over a cross-sectional region of the semiconductor layer is then formed to provide confinement of light in the lateral direction. In the preferred method, the growth of single crystal semiconductor upon the insulator is achieved by a vapor-phase lateral epitaxial overgrowth technique.Devices fabricated according to the method are also disclosed.

Abstract: A method of applying an electrical contact and an anodic reflection coating to an n.sup.+ layer of a direct gap semiconductor device, comprising applying an anodizable metal contact to the n.sup.+ layer and thereafter anodizing the n.sup.+ layer whereby its thickness is reduced and an antireflection layer is formed thereover.

Abstract: Improvements in shallow-homojunction solar cells based upon a plurality of layers of a direct gap semiconductor material such as GaAs, as well as their fabrication, are disclosed. The shallow-homojunction solar cells have a n.sup.+ /p/p.sup.+ structure in which the n.sup.+ top layer is limited to a thickness which permits significant carrier generation to occur in a lower semiconductor layer. An anodic antireflection coating is applied over the n.sup.+ top layer, and a particularly preferred method for applying the antireflection coating is by anodization. These solar cells can be grown on relatively inexpensive substrates, if desired, such as silicon or germanium.