Abstract: A first stack of distributed Bragg mirrors having alternating layers of aluminum gallium arsenide differing in concentrations of an aluminum are disposed on a surface of a substrate with a first plurality of continuous gradient layers positioned between the alternating layers of differing aluminum concentrations to dynamically move the aluminum concentration from one of the alternating layer to another alternating layers. A first cladding region is disposed on the first stack of distributed Bragg mirrors. An active region is disposed on the first cladding region with a second cladding region being dispose on the active region.

Abstract: A method of fabricating VCSELs including the steps of epitaxially growing a first mirror stack of a first conductivity type, an active region on the first mirror stack, and a first portion of a second mirror stack of a second conductivity type on the active region. A dielectric layer is then formed on the first portion of the second mirror stack, patterned to define an operating region and a remaining portion of the second mirror stack is epitaxially grown on the first portion to form a complete second mirror stack. Portions of the second mirror stack overlying the dielectric layer are polycrystalline in formation and substantially limit the remaining portion of the second mirror stack to the operating region. The polycrystalline layers can then be removed and electrical contacts formed.

Abstract: A CVD reactor with a flat generally rectangularly shaped susceptor having a leading edge including a curve which is concave in the direction of gas flow through the reactor. The reactor produces epitaxial layers on semiconductor wafers in which the uniformity of the layer is dependent upon the radius of the concave curvature.

Abstract: A top-emitting vertical cavity surface emitting laser with a current blocking layer at the substrate and offset layers in the mirror stack providing an optical waveguide aligned to the injected current distribution.

Abstract: A high efficiency vertical cavity surface emitting laser with first and second mirror stacks and an active area sandwiched therebetween. The second mirror stack is formed into a mesa with exposed end surface and outer sidewalls and a centrally located light emission region. A portion of the mesa adjacent the exposed outer sidewalls has a reduced electrical conductance so as to spread operating current from the outer sidewalls into the centrally located light emission region. The electrical conductance of the portion is reduced by oxidizing or etching the outer sidewalls.

Abstract: A CVD reactor with a flat generally rectangularly shaped susceptor having a leading edge including a curve which is concave in the direction of gas flow through the reactor. The reactor produces epitaxial layers on semiconductor wafers in which the uniformity of the layer is dependent upon the radius of the concave curvature.

Abstract: A vertical cavity surface emitting laser with temperature insensitive threshold current is constructed with a peak gain at a predetermined wavelength and with a Fabry-Perot resonance at a wavelength higher than the predetermined wavelength of the peak gain. As operating temperatures rise the peak gain is reduced but the Fabry-Perot mode moves closer to the peak gain to maintain the current substantially constant.