摘要:
A VCSEL with undoped mirrors. An essentially undoped bottom DBR mirror is formed on a substrate. A periodically doped first conduction layer region is formed on the bottom DBR mirror. The first conduction layer region is heavily doped at a location where the optical electric field is at about a minimum. An active layer, including quantum wells, is on the first conduction layer region. A periodically doped second conduction layer region is connected to the active layer. The second conduction layer region is heavily doped where the optical electric field is at a minimum. An aperture is formed in the epitaxial structure above the quantum wells. A top mirror coupled to the periodically doped second conduction layer region. The top mirror is essentially undoped and formed in a mesa structure. An oxide is formed around the mesa structure to protect the top mirror during wet oxidation processes.
摘要:
A Distributed Bragg Reflector (DBR) that has relatively low light absorption, relatively low electrical resistance, and/or relatively good thermal conductivity. The DBR may include a first mirror layer and a second mirror layer, with an interface therebetween. A step transition is provided in the aluminum concentration and in the doping concentration at or near the interface between the first mirror layer and the second mirror layer. To reduce optical absorption, the interface between the first and second mirror layers may be positioned at or near a null in the optical electric field within the DBR. A graded junction may also be provided. The graded junction may be more lightly doped, have a graded aluminum concentration, and may be placed at or near a peak in the optical electric field.
摘要:
Methods and systems produce flattening layers associated with nitrogen-containing quantum wells and prevent 3-D growth of nitrogen containing layers using controlled group V fluxes and temperatures. MEE (Migration Enhanced Epitaxy) is used to form a flattening layer upon which a quantum well is formed and thereby enhance smoothness of quantum well interfaces and to achieve narrowing of the spectrum of light emitted from nitrogen containing quantum wells. MEE is performed by alternately depositing single atomic layers of group III and V materials at a given group V flux and then raising the group V flux to saturate the surface of the flattening layer with the group V material. A cap layer is also formed over the quantum well. Where nitrogen is used, the systems incorporate a mechanical means of preventing nitrogen from entering the MBE processing chamber, such as a gate valve.
摘要:
A VCSEL with nearly planar intracavity contact. A bottom DBR mirror is formed on a substrate. A first conduction layer region is formed on the bottom DBR mirror. An active layer, including quantum wells, is on the first conduction layer region. A trench is formed into the active layer region. The trench is formed in a wagon wheel configuration with spokes providing mechanical support for the active layer region. The trench is etched approximately to the first conduction layer region. Proton implants are provided in the wagon wheel and configured to render the spokes of the wagon wheel insulating. A nearly planar electrical contact is formed as an intracavity contact for connecting the bottom of the active region to a power supply. The nearly planar electrical contact is formed in and about the trench.
摘要:
MBE nitrogen sources of dimethylhydrazine, tertiarybutlyhydrazine, nitrogentrifloride, and NHx radicals. Those nitrogen sources are beneficial in forming nitrogen-containing materials on crystalline subtrates using MBE. Semiconductor lasers in general, and VCSEL in particular, that have nitrogen-containing layers can be formed using such nitrogen sources.
摘要:
This disclosure concerns devices such as DBRs, one example of which includes at least one first mirror layers having an oxidized region extending from an edge of the DBR to an oxide termination edge that is situated greater than a first distance from the edge of the DBR. The DBR also includes at least one second mirror layer having an oxidized region extending from the edge of the DBR to an oxide termination edge that is situated less than a second distance from the edge of the DBR, such that the first distance is greater than the second distance. Additionally, a first mirror layer includes an oxidizable material at a concentration that is higher than the concentration of the oxidizable material in any of the second mirror layers. Finally, a first mirror layer is doped with an impurity at a higher level than one of the second mirror layers.
摘要:
The invention is generally concerned with vertical cavity surface emitting lasers. In one example, the vertical cavity surface emitting laser includes, among other things, an upper mirror structure having a metal contact, a top mirror above the metal contact, and a semiconductive top DBR having an insulation region, wherein the top DBR is no more than 3.5 microns thick and is disposed below the metal contact. Thus, the top DBR is sufficiently thick as to enable adequate current spreading, but thin enough to enable fabrication of an isolation region using relatively low energy ion implantation or relatively shallow etching.
摘要:
A vertical cavity surface emitting laser (VCSEL) in which a higher order lasing mode produces a Gaussian-like single mode far field beam intensity pattern. Such a VCSEL includes a protective surface deposition on a VCSEL structure, and phase filter elements on the surface deposition. The surface deposition and the phase filter elements implement an optical phase filter that induces optical path difference such that a single mode far field beam intensity pattern results when the VCSEL operates in a higher order lasing mode. The VCSEL can include structures that enhance a selected higher-order operating mode and/or that suppress unwanted operating modes.
摘要:
A process for making a laser structure. The process is for the fabrication of a laser device such a vertical cavity surface emitting laser (VCSEL). The structures made involve dielectric and spin-on material planarization over wide and narrow trenches, coplanar contacts, non-coplanar contacts, thick and thin pad dielectric, air bridges and wafer thinning.
摘要:
An oxide-confined VCSELs having a distributed Bragg reflector with a heavily doped high Al content oxide aperture forming layer disposed between a low Al content first layer and a medium Al content second layer. Between the first layer and the oxide aperture forming layer there may be a thin transition region wherein the Al content changes from a higher Al content to a lower Al content. In some embodiments, the Al concentration from the oxide aperture forming layer to the second layer may occur in a step. The oxide aperture forming layer may be disposed at or near a null or a node of the electric field produced by resonant laser light. During the oxidization of the oxide aperture forming layer, all or some of the other aluminum bearing DBR layers may also become oxidized, but to a substantially lesser degree. The junction between the oxidized portion and un-oxidized portion of these layers is believed to reduce the stability and/or reliability of the device. To alleviate this, the present invention contemplates providing an implant, etch or other suitable process to reduce or eliminate one or more electrical artifacts associated with the junction between the oxidized portion and un-oxidized portion of these layers as well as reducing the oxidation of other aluminum bearing layers of the DBR.