Abstract: A method for providing an epitaxial layer of a first material over a substrate comprising a second material having a lattice constant different from that of the first material. In the method of the present invention, a first layer of the first material is grown on the substrate. A portion of the first layer is treated to render that portion amorphous. The amorphous portion is then annealed at a temperature above the recrystallization point of the amorphous portion, but below the melting point of the crystallized portion of the first layer thereby recrystallizing the amorphous portion of the first layer. The first layer may rendered amorphous by ion implantation. The method may be used to generate GaN layers on sapphire having fewer dislocations than GaN layers generated by conventional deposition techniques.

Abstract: A VCSEL with a near planar top surface on which the top electrode is deposited. A VCSEL according to the present invention includes a top electrode, a top mirror having a top surface, a light generation region, and a bottom mirror for reflecting light toward the top mirror. At least one of the mirrors includes a plurality of planar electrically conducting layers having different indices of refraction. In addition, at least one of the layers includes an oxidizable material. To expose this layer to an oxidizing agent (thereby converting the material to an electrical insulator), three or more holes are etched down from the top surface of the VCSEL to the layer containing the oxidizable material. The oxidizing agent is then introduced into the top of these holes. The partial oxidation of the layer converts the layer to one having a conducting region surrounded by an electrically insulating region, the conducting region being positioned under the top electrode.

Abstract: A method for fabricating transparent substrate vertical cavity surface emitting lasers ("VCSEL"s) using wafer bonding is described. The VCSELs have their active layers located much more closely to a heat sink than is possible in known absorbing substrate VCSELs. The improved heat transport from the active layer to the heat sink permits higher current operation with increased light output as a result of the lower thermal impedance of the system. Alternatively, the same light output can be obtained from the wafer bonded VCSEL at lower drive currents. Additional embodiments use wafer bonding to improve current crowding, current and/or optical confinement in a VCSEL and to integrate additional optoelectronic devices with the VCSEL.

Abstract: A VCSEL 101 comprising an optical cavity having an optical loss and a loss-determining element 117 coupled to the optical cavity. The loss-determining element 117 progressively increases the optical loss of the optical cavity with increasing lateral distance from the optical axis 105. The optical cavity includes a first mirror region 111, a second mirror region 107, a plane light-generating region 125 sandwiched between the first mirror region 111 and the second mirror region 107, perpendicular to the optical axis 105, and an element 113 that defines the lateral extent of the optical cavity in the plane of the light-generating region 125. The first mirror region 111 and the second mirror region 107 are both conductive and have opposite conductivity modes.

Abstract: A method for fabricating transparent substrate vertical cavity surface emitting lasers ("VCSEL"s) using wafer bonding is described. The VCSELs have their active layers located much more closely to a heat sink than is possible in known absorbing substrate VCSELs. The improved heat transport from the active layer to the heat sink permits higher current operation with increased light output as a result of the lower thermal impedance of the system. Alternatively, the same light output can be obtained from the wafer bonded VCSEL at lower drive currents. Additional embodiments use wafer bonding to improve current crowding, current and/or optical confinement in a VCSEL and to integrate additional optoelectronic devices with the VCSEL.

Abstract: A visible semiconductor laser. The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1.lambda.) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%.

Abstract: A semiconductor light-emitting device and method. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL).

Abstract: A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of .lambda./2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In.sub.z (Al.sub.y Ga.sub.1-y).sub.1-z P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m .lambda./2n.sub.eff where m is an integer and n.sub.