| Patent application number | Description | Published |
|---|
| 20080279234 | Alignment of lasing wavelength with wavelength conversion peak using modulated wavelength control signal - According to one embodiment of the present invention, a programmable light source comprises one or more semiconductor lasers, a wavelength conversion device, and a laser controller. The controller is programmed to operate the semiconductor laser using a modulated feedback control signal. The wavelength control signal is adjusted based on the results of a comparison of a detected intensity signal with a feedback signal to align the lasing wavelength with the conversion efficiency peak of the wavelength conversion device. Laser controllers and projections systems operating according to the control concepts of the present invention are also provided. | 11-13-2008 |
| 20080299495 | Methods of fabricating metal contact structures for laser diodes using backside UV exposure - Methods of fabricating a metal contact structure for a laser diodes are provided, wherein the method comprises providing a UV transparent semiconductor substrate, a UV transparent semiconductor epilayer defining a ridge disposed between etched epilayer edges, the epilayer being disposed over the UV transparent semiconductor substrate, and a UV opaque metal layer disposed over the epilayer ridge, applying at least one photoresist layer (positive photoresist, image reversal photoresist, or negative photoresist) over the opaque metal layer and epilayer edges, and selectively developing regions of the photoresist layer via backside exposure to UV light with the opaque metal layer used as a photolithographic mask. | 12-04-2008 |
| 20080299691 | GaN lasers on ALN substrates and methods of fabrication - Ga(In)N-based laser structures and related methods of fabrication are proposed where Ga(In)N-based semiconductor laser structures are formed on AlN or GaN substrates in a manner that addresses the need to avoid undue tensile strain in the semiconductor structure. In accordance with one embodiment of the present invention, a Ga(In)N-based semiconductor laser is provided on an AlN or GaN substrate provided with an AlGaN lattice adjustment layer where the substrate, the lattice adjustment layer, the lower cladding region, the active waveguiding region, the upper cladding region, and the N and P type contact regions of the laser form a compositional continuum in the semiconductor laser. Additional embodiments are disclosed and claimed. | 12-04-2008 |
| 20090086775 | Laser source with interdigital heater electrodes and underlying current confinement layer - A semiconductor laser source is provided wherein the wavelength selective section of the laser diode comprises a P+ type current confinement layer and first and second sets of interdigital heater electrodes formed over the current confinement layer. Individual electrode digits of the first and second sets of interdigital heater electrodes alternate in succession along a direction of optical propagation defined by the active waveguide layer of the laser diode. The first set of interdigital heater electrodes are positively or negatively biased relative to the laser diode cathode and relative to the second set of interdigital heater electrodes such that the relative bias is either less than the forward bias turn-on voltage of the P-N junction or has an absolute value less than the reverse break-down voltage of the P-N junction. | 04-02-2009 |
| 20090086784 | Quantum well intermixing - Embodiments of a method of quantum well intermixing (QWI) comprise providing a wafer comprising upper and lower epitaxial layers, which each include barrier layers, and a quantum well layer disposed between the upper and lower epitaxial layers, applying at least one sacrificial layer over the upper epitaxial layer, and forming a QWI enhanced region and a QWI suppressed region by applying a QWI enhancing layer over a portion of the sacrificial layer, wherein the portion under the QWI enhancing layer is the QWI enhanced region, and the other portion is the QWI suppressed region. The method further comprises the steps of applying a QWI suppressing layer over the QWI enhanced region and the QWI suppressed region, and annealing at a temperature sufficient to cause interdiffusion of atoms between the quantum well layer and the barrier layers of the upper epitaxial layer and the lower epitaxial layer. | 04-02-2009 |
| 20090101924 | Gallium nitride semiconductor device on SOI and process for making same - Methods and apparatus for producing a gallium nitride semiconductor on insulator structure include: bonding a single crystal silicon layer to a transparent substrate; and growing a single crystal gallium nitride layer on the single crystal silicon layer. | 04-23-2009 |
| 20090246707 | Semiconductor buried grating fabrication method - Methods for forming grating profiles in semiconductor laser structures comprise the steps of providing a semiconductor wafer comprising a wafer substrate, an etch stop layer disposed over the wafer substrate, a grating layer disposed over the etch stop layer, an etch mask layer disposed over the grating layer, and a photoresist layer disposed over the etch mask layer, forming a photoresist grating pattern, transferring the photoresist grating pattern into the grating layers via dry etching, and removing the photoresist layer, selectively wet etching the grating layer to form the grating profile in the grating layer. The placement of the grating layer between the etch mask and etch stop layers controls the selective wet etching step. The method also comprises removing the etch mask layer via selective wet etching without altering the grating profile, and regrowing an upper cladding layer to produce the semiconductor laser structure. | 10-01-2009 |
| 20100150193 | MQW Laser Structure Comprising Plural MQW Regions - Multi-quantum well laser structures are provided comprising active and/or passive MQW regions. Each of the MQW regions comprises a plurality of quantum wells and intervening barrier layers. Adjacent MQW regions are separated by a spacer layer that is thicker than the intervening barrier layers. The bandgap of the quantum wells is lower than the bandgap of the intervening barrier layers and the spacer layer. The active region may comprise active and passive MQWs and be configured for electrically-pumped stimulated emission of photons or it may comprises active MQW regions configured for optically-pumped stimulated emission of photons. | 06-17-2010 |
| 20100260215 | Split Control Of Front And Rear DBR Grating Portions - A method is provided for controlling a DBR laser diode wherein front and rear DBR section heating elements are controlled such that the reflectivity of the rear grating portion of the DBR section is lower than the reflectivity of the front grating portion of the DBR section. In this manner, lasing mode selection is dominated by the front grating portion and the front DBR section heating element can be controlled for wavelength tuning. In addition, the rear DBR section heating element can be controlled to narrow the spectral bandwidth of the DBR reflection spectra. Additional embodiments are disclosed and claimed. | 10-14-2010 |
| 20100265982 | Fracture Resistant Metallization Pattern For Semiconductor Lasers - Metallization patterns are provided to reduce the probability of chip fracture in semiconductor lasers. According to one embodiment disclosed herein, the pad edges of a metallization pattern extend across a plurality of crystallographic planes in the laser substrate. In this manner, cracks initiated at any given stress concentration would need to propagate across many crystallographic planes in the substrate to reach a significant size. Additional embodiments of the present disclosure relate to the respective geometries and orientations of adjacent pairs of contact pads. Still further embodiments are disclosed and claimed. | 10-21-2010 |
| 20110049469 | Enhanced P-Contacts For Light Emitting Devices - An optoelectronic light emitting semiconductor device is provided comprising an active region, a p-type Group III nitride layer, an n-type Group III nitride layer, a p-side metal contact layer, an n-side metal contact layer, and an undoped tunneling enhancement layer. The p-side metal contact layer is characterized by a work function W satisfying the following relation: | 03-03-2011 |
| 20110072886 | Gas Sensor Based On Photoacoustic Detection - A photoacoustic gas detector and photoacoustic gas detection method are disclosed. The detector includes a laser source, an acoustic resonator, and at least one tuning fork positioned along a longitudinal length of the resonator. The detector is capable of performing fast measurements of the concentration of one or more target gases over a broad temperature range. | 03-31-2011 |
| 20110128984 | NATIVE GREEN LASER SEMICONDUCTOR DEVICES - A semiconductor laser device operable to emit light having a desired wavelength in the green spectral range. The semiconductor laser device may include a pumping source and a laser structure including a substrate, a first cladding layer, and one or more active region layers. The one or more active region layers include a number of quantum wells having a spontaneous emission peak wavelength that is greater than about 520 nm at a reference pumping power density. The pumping source is configured to pump each quantum well at a pumping power density such that a stimulated emission peak of each quantum well is within the green spectral range, and the number of quantum wells within the one or more active region layers is such that a net optical gain of the quantum wells is greater than a net optical loss coefficient at the desired wavelength in the green spectral range. | 06-02-2011 |
