Patents by Inventor Steven D. Lester

Steven D. Lester 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).

  • Patent number: 7581863
    Abstract: A light source and a display utilizing the same are disclosed. The light source includes a laser, a light pipe, and an optical fiber. The light pipe includes a layer of transparent material having a top surface, a bottom surface, and a first edge. The first optical fiber couples light from the laser to the first edge at a first location. The light is injected into the light pipe such that the light is reflected from the top surface and the light pipe includes a plurality of scattering centers that scatter the light through the top surface. The laser can be in thermal contact with a heat sink placed at a location that is adapted for dissipating heat. The light source can include a plurality of lasers in a color display. The light from the various lasers can be mixed before it reaches the light pipe or in the light pipe.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: September 1, 2009
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventor: Steven D. Lester
  • Patent number: 7573074
    Abstract: An electrode structure is disclosed for enhancing the brightness and/or efficiency of an LED. The electrode structure can have a metal electrode and an optically transmissive thick dielectric material formed intermediate the electrode and a light emitting semiconductor material. The electrode and the thick dielectric cooperate to reflect light from the semiconductor material back into the semiconductor so as to enhance the likelihood of the light ultimately being transmitted from the semiconductor material. Such LED can have enhanced utility and can be suitable for uses such as general illumination.
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: August 11, 2009
    Assignee: Bridgelux, Inc.
    Inventors: Frank T. Shum, William W. So, Steven D. Lester
  • Publication number: 20090179229
    Abstract: An ohmic contact in accordance with the invention includes a layer of p-type GaN-based material. A first layer of a group II-VI compound semiconductor is located adjacent to the layer of p-type GaN-based material. The ohmic contact further includes a metal layer that provides metal contact. A second layer of a different II-VI compound semiconductor is located adjacent to the metal layer.
    Type: Application
    Filed: January 20, 2009
    Publication date: July 16, 2009
    Applicant: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Jeffrey N. Miller, David P. Bour, Virginia M. Robbins, Steven D. Lester
  • Publication number: 20090146165
    Abstract: A light emitting device, a wafer for making the same, and method for fabricating the same are disclosed. The device and wafer include a first layer of a first conductivity type, an active layer, and a layer of a second conductivity type. The active layer overlies the first layer, the active layer generating light. The second layer overlies the active layer, the second layer having a first surface in contact adjacent to the active layer and a second surface having a surface that includes features that scatter light striking the second surface. A layer of transparent electrically conducing material is adjacent to the second surface and covered by a first layer of a dielectric material that is transparent to the light generated by the active layer. A mirror layer that has a reflectivity greater than 90 percent is deposited on the first layer of dielectric material.
    Type: Application
    Filed: December 6, 2007
    Publication date: June 11, 2009
    Inventors: Ghulam Hasnain, Steven D. Lester
  • Patent number: 7495314
    Abstract: An ohmic contact in accordance with the invention includes a layer of p-type GaN-based material. A first layer of a group II-VI compound semiconductor is located adjacent to the layer of p-type GaN-based material. The ohmic contact further includes a metal layer that provides metal contact. A second layer of a different II-VI compound semiconductor is located adjacent to the metal layer.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: February 24, 2009
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Jeffrey N. Miller, David P. Bour, Virginia M. Robbins, Steven D. Lester
  • Patent number: 7473941
    Abstract: A light-emitting device comprises an active region configured to generate light in response to injected charge, and an n-type material layer and a p-type material layer, wherein at least one of the n-type material layer and the p-type material layer is doped with at least two dopants, at least one of the dopants having an ionization energy higher than the ionization energy level of the other dopant.
    Type: Grant
    Filed: August 15, 2005
    Date of Patent: January 6, 2009
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Virginia M. Robbins, Steven D. Lester, Jeffrey N. Miller, David P. Bour
  • Publication number: 20080303053
    Abstract: A device having a carrier, a light-emitting structure, and first and second electrodes is disclosed. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength in the active layer when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The first and second electrodes are bonded to the surfaces of the p-type and n-type GaN layers that are not adjacent to the active layer. The n-type GaN layer has a thickness less than 1.25 ?m. The carrier is bonded to the light emitting structure during the thinning of the n-type GaN layer. The thinned light-emitting structure can be transferred to a second carrier to provide a device that is analogous to conventional LEDs having contacts on the top surface of the LED.
    Type: Application
    Filed: June 11, 2007
    Publication date: December 11, 2008
    Inventors: Steven D. Lester, Frank T. Shum
  • Publication number: 20080035936
    Abstract: A light-emitting device and the method for making the same are disclosed. The device includes a substrate, a light-emitting structure and a light scattering layer. The light-emitting structure includes an active layer sandwiched between a p-type GaN layer and an n-type GaN layer, the active layer emitting light of a predetermined wavelength when electrons and holes from the n-type GaN layer and the p-type GaN layer, respectively, combine therein. The light scattering layer includes a GaN crystalline layer characterized by an N-face surface. The N-face surface includes features that scatter light of the predetermined wavelength. The light-emitting structure is between the N-face surface and the substrate.
    Type: Application
    Filed: August 14, 2006
    Publication date: February 14, 2008
    Inventor: Steven D. Lester
  • Patent number: 7273798
    Abstract: A gallium nitride device substrate comprises a layer of gallium nitride containing an additional lattice parameter altering element located over a substitute substrate.
    Type: Grant
    Filed: August 1, 2005
    Date of Patent: September 25, 2007
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Steven D. Lester, Virginia M. Robbins, Scott W. Corzine
  • Patent number: 7095052
    Abstract: The efficiency of LEDs is increased by incorporating multiple active in series separated by tunnel junction diodes. This also allows the LEDs to operate at longer wavelengths.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: August 22, 2006
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventor: Steven D. Lester
  • Patent number: 6953702
    Abstract: Vertical cavity optical devices, and a method of manufacturing therefor, are provided where the method includes partially forming a first vertical cavity optical device on a wafer, adjusting the lasing wavelength of the first vertical cavity optical device, and fixing the lasing wavelength of the first vertical cavity optical device to complete the forming thereof.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: October 11, 2005
    Assignee: Agilent Technologies, Inc.
    Inventors: Jeffrey N. Miller, Virginia M. Robbins, Steven D. Lester
  • Patent number: 6806110
    Abstract: A monolithic array of vertical cavity lasers with different emission wavelengths on a single wafer, and method of manufacture therefor, is provided. A first reflector is over the semiconductor substrate with a photoactive semiconductor layer. A reflector support defines first and second air gaps with the photoactive semiconductor layer. The second and third air gaps are made to be different from each other by geometric differences in the reflector support structure. Second and third reflectors are formed over the reflector support whereby a first laser is formed by the first reflector, the photoactive semiconductor structure, the first air gap, and the second reflector and whereby a second laser is formed by the first reflector, the photoactive semiconductor structure, the second air gap, and the third reflector. The emission wavelengths of the first and second lasers are different because of the different sizes of the first and second air gaps.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: October 19, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Steven D. Lester, Virginia M. Robbins, Jeffrey N. Miller
  • Publication number: 20030214992
    Abstract: A monolithic array of vertical cavity lasers with different emission wavelengths on a single wafer, and method of manufacture therefor, is provided. A first reflector is over the semiconductor substrate with a photoactive semiconductor layer. A reflector support defines first and second air gaps with the photoactive semiconductor layer. The second and third air gaps are made to be different from each other by geometric differences in the reflector support structure. Second and third reflectors are formed over the reflector support whereby a first laser is formed by the first reflector, the photoactive semiconductor structure, the first air gap, and the second reflector and whereby a second laser is formed by the first reflector, the photoactive semiconductor structure, the second air gap, and the third reflector. The emission wavelengths of the first and second lasers are different because of the different sizes of the first and second air gaps.
    Type: Application
    Filed: May 16, 2002
    Publication date: November 20, 2003
    Inventors: Steven D. Lester, Virginia M. Robbins, Jeffrey N. Miller
  • Publication number: 20030215969
    Abstract: Vertical cavity optical devices, and a method of manufacturing therefor, are provided where the method includes partially forming a first vertical cavity optical device on a wafer, adjusting the lasing wavelength of the first vertical cavity optical device, and fixing the lasing wavelength of the first vertical cavity optical device to complete the forming thereof.
    Type: Application
    Filed: May 16, 2002
    Publication date: November 20, 2003
    Inventors: Jeffrey N. Miller, Virginia M. Robbins, Steven D. Lester
  • Patent number: 6573537
    Abstract: An inverted III-nitride light-emitting device (LED) with highly reflective ohmic contacts includes n- and p-electrode metallizations that are opaque, highly reflective, and provide excellent current spreading. The n- and p-electrodes each absorb less than 25% of incident light per pass at the peak emission wavelength of the LED active region.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: June 3, 2003
    Assignee: Lumileds Lighting, U.S., LLC
    Inventors: Daniel A. Steigerwald, Steven D. Lester, Jonathan J. Wierer, Jr.
  • Patent number: 6307218
    Abstract: A light emitting device includes a heterojunction having a p-type layer and an n-type layer. The n-electrode is electrically connected to the n-type layer while the p-electrode is electrically connected to the p-type layer. The p and n-electrodes are positioned to form a region having uniform light intensity.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: October 23, 2001
    Assignee: LumiLeds Lighting, U.S., LLC
    Inventors: Daniel A. Steigerwald, Serge L Rudaz, Kyle J. Thomas, Steven D. Lester, Paul S. Martin, William R. Imler, Robert M. Fletcher, Fred A. Kish, Jr., Steven A. Maranowski
  • Patent number: 6291839
    Abstract: The invention is an AlInGaN light-emitting device (LED) that includes a p-type contact made of highly-reflective material with closely-spaced openings that increase light extraction efficiency. The minimum dimension of the openings is ¼ of the wavelength of the emitted light and is preferably comparable to the distance current flows laterally in the p-layers of the device. The openings in the metal occupy 20-80% of the top surface of the contact and are finely spaced to achieve transparency and uniform light emission. An optional dielectric encapsulant may be deposited over the p-type contact to improve the contact's adhesion by tacking it down at regular intervals, and to improve light extraction. The surface of the epitaxial layers may be etched in the openings to scatter light in the semiconductor, increasing light extraction. A reflective layer may be applied to the bottom surface of the LED to increase the light extraction efficiency.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: September 18, 2001
    Assignee: LuliLeds Lighting, U.S. LLC
    Inventor: Steven D. Lester
  • Patent number: 6258618
    Abstract: The invention is an AlInGaN light-emitting device (LED) that includes a p-type contact made of highly-reflective material with closely-spaced openings that increase light extraction efficiency. The minimum dimension of the openings is ¼ of the wavelength of the emitted light and is preferably comparable to the distance current flows laterally in the p-layers of the device. The openings in the metal occupy 20-80% of the top surface of the contact and are finely spaced to achieve transparency and uniform light emission. An optional dielectric encapsulant may be deposited over the p-type contact to improve the contact's adhesion by tacking it down at regular intervals, and to improve light extraction. The surface of the epitaxial layers may be etched in the openings to scatter light in the semiconductor, increasing light extraction. A reflective layer may be applied to the bottom surface of the LED to increase the light extraction efficiency.
    Type: Grant
    Filed: January 14, 2000
    Date of Patent: July 10, 2001
    Assignee: Lumileds Lighting, US, LLC
    Inventor: Steven D. Lester
  • Patent number: 6091085
    Abstract: An LED having a higher light coupling efficiency than prior art devices, particularly those based on GaN. An LED according to the present invention includes a substrate having a top surface, a first layer of a semiconducting material deposited on the top surface of the substrate, a light generation region deposited on the first layer, and a second layer of semiconducting material deposited on the first layer. Electrical contacts are connected to the first and second layers. In one embodiment, the top surface of the substrate includes protrusions and/or depressions for scattering light generated by the light generation region. In a second embodiment, the surface of the second layer that is not in contact with the first layer includes a plurality of protrusions having facets positioned such that at least a portion of the light generated by light generation layer strikes the facets and exits the surface of the second layer.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: July 18, 2000
    Assignee: Agilent Technologies, Inc.
    Inventor: Steven D. Lester
  • Patent number: 5902688
    Abstract: This disclosure provides an electroluminescent ("EL") display device having anode, cathode, insulator and organic EL layers. The anode and cathode layers sandwich the other two layers, and the insulator layer is patterned to selectively block flow of current through the EL layers, and thereby locally block generation of light. The patterned insulator layer allows a single panel to display multiple visual attributes, yet does not require electrode patterning. The patterned insulator can be fabricated using photoresist exposure and development procedures. The photoresist is laid on top of a commercially available substrate/electrode layered pair, and is developed to create an assembly that can be completed in a single vacuum deposition process.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: May 11, 1999
    Assignee: Hewlett-Packard Company
    Inventors: Homer Antoniadis, Steven D. Lester, Jeffrey N. Miller