Patents by Inventor Michael Kneissl

Michael Kneissl has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070108456
    Abstract: A GaN/AlN superlattice is formed over a GaN/sapphire template structure, serving in part as a strain relief layer for growth of subsequent layers (e.g., deep UV light emitting diodes). The GaN/AlN superlattice mitigates the strain between a GaN/sapphire template and a multiple quantum well heterostructure active region, allowing the use of high Al mole fraction in the active region, and therefore emission in the deep UV wavelengths.
    Type: Application
    Filed: February 17, 2006
    Publication date: May 17, 2007
    Inventors: William Wong, Michael Kneissl, Zhihong Yang, Mark Teepe, Cliff Knollenberg
  • Publication number: 20070111345
    Abstract: A system and method for providing improved surface quality following removal of a substrate and template layers from a semiconductor structure provides an improved surface quality for a layer (such as a quantum well heterostructure active region) prior to bonding a heat sink/conductive substrate to the structure. Following the physical removal of a sapphire substrate, a sacrificial coating such as a spin-coat polymer photoresist is applied to an exposed GaN surface. This sacrificial coating provides a planar surface, generally parallel to the planes of the interfaces of the underlying layers. The sacrificial coating and etching conditions are selected such that the etch rate of the sacrificial coating approximately matches the etch rate of GaN and the underlying layers, so that the physical surface profile during etching approximates the physical surface profile of the sacrificial coating prior to etching.
    Type: Application
    Filed: February 17, 2006
    Publication date: May 17, 2007
    Inventors: William Wong, Michael Kneissl, Mark Teepe
  • Patent number: 7138648
    Abstract: A pair of undoped spacer layers are provided adjacent to, or near to, a single quantum well aluminum gallium nitride active region. In various exemplary embodiments, the undoped spacer layers are provided between the single quantum well aluminum gallium nitride active region and carrier confinement layers. The undoped spacer layers reduce the threshold current for the laser device and improve the output characteristics.
    Type: Grant
    Filed: December 17, 2003
    Date of Patent: November 21, 2006
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Michael A. Kneissl, David W. Treat
  • Patent number: 7122799
    Abstract: A system for conducting a polymerase chain reaction (PCR) assay upon a collection of samples is disclosed. The PCR assay is performed by absorption detection. The system includes a multi-well plate which is adapted to retain a collection of sample wells. This system includes a thermal cycler for the multi-well plate. The system additionally includes a collection of photodetectors, and a corresponding number of light sources. The light sources are positioned such that light emitted from each of the respective light sources passes through a corresponding well retained in the multi-well plate and to a corresponding photodetector. The system also includes a processor or other means for analyzing the output signals from the photodetectors. In certain versions of the system, ultra-violet light is used.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: October 17, 2006
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Huangpin Ben Hsieh, Michael A. Kneissl
  • Patent number: 7123637
    Abstract: A nitride-based laser diode structure utilizing a single GaN:Mg waveguide/cladding layer, in place of separate GaN:Mg waveguide and AlGaN:Mg cladding layers used in conventional nitride-based laser diode structures. When formed using an optimal thickness, the GaN:Mg layer produces an optical confinement that is comparable to or better than conventional structures. A thin AlGaN tunnel barrier layer is provided between the multiple quantum well and a lower portion of the GaN:Mg waveguide layer, which suppresses electron leakage without any significant decrease in optical confinement. A split-metal electrode is formed on the GaN:Mg upper waveguide structure to avoid absorption losses in the upper electrode metal. A pair of AlGaN:Si current blocking layer sections are located below the split-metal electrode sections, and separated by a gap located over the active region of the multiple quantum well.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: October 17, 2006
    Assignee: Xerox Corporation
    Inventors: Michael A. Kneissl, David P. Bour, Linda T. Romano, Christian G. Van de Walle
  • Patent number: 7087444
    Abstract: A method of forming an integrated microelectronic device and a micro channel is provided. The method offers an inexpensive way of integrating devices that are usually incompatible during fabrication, a microchannel and a microelectronic structure such as an electro-optic light source, a detector or a MEMs device into a single integrated structure.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: August 8, 2006
    Assignee: Palo Alto Research Center Incorporated
    Inventors: William S. Wong, Michael L. Chabinyc, Steven E. Ready, Michael A. Kneissl, Mark R. Teepe
  • Publication number: 20060133443
    Abstract: Lasers, such as in laser structures, can include two or more semiconductor structures that are substantially identical or that include the same semiconductor material and have substantially the same geometry, such as in closely spaced dual-spot two-beam or quad-spot four-beam lasers. The lasers can also include differently structured current flow or contact structures or different wavelength control structures. For example, current flow or contact structures can be differently structured to prevent or otherwise affect phase locking, such as by causing different threshold currents and different operating temperatures.
    Type: Application
    Filed: December 17, 2004
    Publication date: June 22, 2006
    Inventors: Christopher Chua, Michael Kneissl, Patrick Maeda, Noble Johnson, Ross Bringans, John Northrup, David Biegelsen
  • Publication number: 20060126688
    Abstract: A novel indium gallium nitride laser diode is described. The laser uses indium in either the waveguide layers and/or the cladding layers. It has been found that InGaN waveguide or cladding layers enhance optical confinement with very small losses. Furthermore, the use of InGaN waveguide or cladding layers can improve the structural integrity of active region epilayers because of reduced lattice mismatch between waveguide layers and the active region.
    Type: Application
    Filed: October 28, 2005
    Publication date: June 15, 2006
    Inventor: Michael Kneissl
  • Publication number: 20060092413
    Abstract: An improved method of analyzing target analytes in a sample is described. The method is based on anti-resonant guided optical waveguides which enables a strongly improved light-target interaction since the light can be guided within the target-containing medium. The light-target interaction can be monitored by many different means to determine characteristics of the target analyte. The anti-resonant waveguide concept is suitable for a large variety of characterization methods and combinations of them, since it is relatively unaffected by changes to both wavelength and film thickness.
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Inventors: Peter Kiesel, Oliver Wolst, Michael Kneissl, H. Hsieh
  • Patent number: 7031365
    Abstract: A locally-outcoupled optical resonator has whispering gallery modes existing in a nearly circular resonator. Light is outcoupled by providing a local perturbing feature on the perimeter of the locally-outcoupled cavity resonator. The perturbing feature provides an outcoupling or loss mechanism that asymmetrically interacts with circulating whispering gallery modes, thereby making the resonator capable of uni-directional output.
    Type: Grant
    Filed: May 2, 2003
    Date of Patent: April 18, 2006
    Assignee: Xerox Corporation
    Inventors: Michael A. Kneissl, Noble M. Johnson, David K. Biegelsen, Richard K. Chang, A. Douglas Stone, Grace D. Chern, Hakan E. Tureci, Joseph Zyss
  • Publication number: 20060046312
    Abstract: A compact sensor for detecting the presence of biological or chemical species includes a microdisk laser and a wavelength shift detector. The microdisk laser is coated with a biological or chemical recognition element, which binds preferentially with a target analyte. Because the recognition element and the target analyte adhere to the sidewall surface of the microdisk laser, they increase the effective diameter of the laser, which shifts the output wavelength by a detectable amount. The presence of a wavelength shift indicates the presence of the target analyte, and the magnitude of the wavelength shift corresponds to the mass load of the target analyte on the sidewall surface of the microdisk laser.
    Type: Application
    Filed: September 1, 2004
    Publication date: March 2, 2006
    Applicant: PALO ALTO RESEARCH CENTER INCOROPORATED
    Inventors: Peter Kiesel, Noble Johnson, Meng Lean, H. Hsieh, Michael Kneissl
  • Patent number: 6990132
    Abstract: A nitride-based laser diode structure utilizing a metal-oxide (e.g., Indium-Tin-Oxide (ITO) or Zinc-Oxide (ZnO)) in place of p-doped AlGaN to form the upper cladding layer. An InGaN laser diode structure utilizes ITO upper cladding structure, with an SiO2 isolation structure formed on opposite sides of the ITO upper cladding structure to provide a lateral index step that is large enough to enable lateral single-mode operation. The lateral index step is further increased by slightly etching the GaN:Mg waveguide layer below the SiO2 isolation structure. An optional p-type current barrier layer (e.g., AlGaN:Mg having a thickness of approximately 20 nm) is formed between the InGaN-MQW region and a p-GaN upper waveguide layer to impede electron leakage from the InGaN-MQW region.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: January 24, 2006
    Assignee: Xerox Corporation
    Inventors: Michael A. Kneissl, Linda T. Romano, Christian G. Van de Walle
  • Patent number: 6967981
    Abstract: A nitride based resonant cavity semiconductor structure has highly reflective mirrors on opposite sides of the active layer. These highly reflective mirrors can be distributed Bragg reflectors or metal terminated layer stacks of dielectric materials. The nitride based resonant cavity semiconductor structure can be vertical cavity surface emitting laser (VCSEL), a light emitting diode (LED), or a photodetector (PD), or a combination of these devices.
    Type: Grant
    Filed: May 30, 2002
    Date of Patent: November 22, 2005
    Assignee: Xerox Corporation
    Inventors: Christopher L. Chua, Michael A. Kneissl, David P. Bour
  • Publication number: 20050224781
    Abstract: A pair of undoped spacer layers are provided adjacent to, or near to, a single quantum well aluminum gallium nitride active region. In various exemplary embodiments, the undoped spacer layers are provided between the single quantum well aluminum gallium nitride active region and carrier confinement layers. The undoped spacer layers reduce the threshold current for the laser device and improve the output characteristics.
    Type: Application
    Filed: December 17, 2003
    Publication date: October 13, 2005
    Applicant: PALO ALTO RESEARCH CENTER, INCORPORATED
    Inventors: Michael Kneissl, David Treat
  • Publication number: 20050135453
    Abstract: A grating-outcoupled microcavity disk resonator has whispering gallery modes existing in a nearly circular resonator. Light is outcoupled by providing a grating region in the plane of the grating-outcoupled microcavity disk resonator. The grating region provides an outcoupling or lass mechanism that symmetrically interacts with the clockwise and counterclockwise whispering gallery modes, thereby making the resonator capable of surface emission.
    Type: Application
    Filed: December 17, 2003
    Publication date: June 23, 2005
    Applicant: PALO ALTO RESEARCH CENTER, INCORPORATED
    Inventors: Michael Kneissl, Noble Johnson, David Biegelsen
  • Publication number: 20050133724
    Abstract: A system for conducting a polymerase chain reaction (PCR) assay upon a collection of samples is disclosed. The PCR assay is performed by absorption detection. The system includes a multi-well plate which is adapted to retain a collection of sample wells. This system includes a thermal cycler for the multi-well plate. The system additionally includes a collection of photodetectors, and a corresponding number of light sources. The light sources are positioned such that light emitted from each of the respective light sources passes through a corresponding well retained in the multi-well plate and to a corresponding photodetector. The system also includes a processor or other means for analyzing the output signals from the photodetectors. In certain versions of the system, ultra-violet light is used.
    Type: Application
    Filed: December 18, 2003
    Publication date: June 23, 2005
    Inventors: Huangpin Hsieh, Michael Kneissl
  • Patent number: 6875627
    Abstract: An index-guided buried heterostructure AlGalnN laser diode provides improved mode stability and low threshold current when compared to conventional ridge waveguide structures. A short period superlattice is used to allow adequate cladding layer thickness for confinement without cracking. The intensity of the light lost due to leakage is reduced by about 2 orders of magnitude with an accompanying improvement in the far-field radiation pattern when compared to conventional structures.
    Type: Grant
    Filed: December 26, 2001
    Date of Patent: April 5, 2005
    Assignee: Xerox Corporation
    Inventors: David P. Bour, Michael A. Kneissl, Linda T. Romano
  • Patent number: 6816528
    Abstract: Method and structure for nitride-based laser diode arrays on a conducting substrate are disclosed. Air-bridge structures are used to make compact laser diode arrays suitable for printer applications. The use of a channel structure architecture allows the making of surface emitting laser diode arrays.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: November 9, 2004
    Assignee: Xerox Corporation
    Inventors: Michael A. Kneissl, David P. Bour, Noble M. Johnson, Jack Walker
  • Publication number: 20040218654
    Abstract: A locally-outcoupled optical resonator has whispering gallery modes existing in a nearly circular resonator. Light is outcoupled by providing a local perturbing feature on the perimeter of the locally-outcoupled cavity resonator. The perturbing feature provides an outcoupling or loss mechanism that asymmetrically interacts with circulating whispering gallery modes, thereby making the resonator capable of uni-directional output.
    Type: Application
    Filed: May 2, 2003
    Publication date: November 4, 2004
    Applicant: Xerox Corporation
    Inventors: Michael A. Kneissl, Noble M. Johnson, David K. Biegelsen, Richard K. Chang, A. Douglas Stone, Grace D. Chern, Hakan E. Tureci, Joseph Zyss
  • Publication number: 20040184496
    Abstract: A nitride-based laser diode structure utilizing a single GaN:Mg waveguide/cladding layer, in place of separate GaN:Mg waveguide and AlGaN:Mg cladding layers used in conventional nitride-based laser diode structures. When formed using an optimal thickness, the GaN:Mg layer produces an optical confinement that is comparable to or better than conventional structures. A thin AlGaN tunnel barrier layer is provided between the multiple quantum well and a lower portion of the GaN:Mg waveguide layer, which suppresses electron leakage without any significant decrease in optical confinement. A split-metal electrode is formed on the GaN:Mg upper waveguide structure to avoid absorption losses in the upper electrode metal. A pair of AlGaN:Si current blocking layer sections are located below the split-metal electrode sections, and separated by a gap located over the active region of the multiple quantum well.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Applicant: Xerox Corporation
    Inventors: Michael A. Kneissl, David P. Bour, Linda T. Romano, Christian G. Van de Walle