Patents by Inventor Dennis R. Alexander

Dennis R. Alexander 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: 20120314214
    Abstract: A material can be analyzed using short pulses by applying a first pulse and a second pulse to the material in which the second pulse is delayed relative to the first pulse. The first and second pulses are directed toward a material along collinear paths, and the material is ablated using the first pulse to cause particles to be emitted from the surface of the material. The emitted particles are atomized and/or ionized using the second pulse, and the radiation from the atomized and/or ionized particles is analyzed.
    Type: Application
    Filed: June 7, 2012
    Publication date: December 13, 2012
    Inventors: DENNIS R. ALEXANDER, TROY ANDERSON, JOHN C. BRUCE, III
  • Patent number: 8247731
    Abstract: Disclosed are systems and methods for directing laser energy to surfaces of materials via elements which have sharp points, and for reducing the adverse effects of particles which become dislodged by scribing and laser machining of materials.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: August 21, 2012
    Assignee: Board of Regents of the University of Nebraska
    Inventors: Dennis R. Alexander, John Bruce, III
  • Patent number: 8189190
    Abstract: Systems and methods are provided for monitoring materials using ultra fast laser pulses. Ultra fast laser pulses, such as femtosecond or attosecond laser pulses, are applied to the materials and laser pulses that result from interactions between the ultra fast laser pulses and the materials are collected. Spectral content of the resulting pulses is generated and presented. The elemental composition of the materials is determined using the spectral content.
    Type: Grant
    Filed: November 2, 2007
    Date of Patent: May 29, 2012
    Assignee: Board of Regents of the University of Nebraska
    Inventor: Dennis R. Alexander
  • Patent number: 7868302
    Abstract: A particle based optical diode having at least two cavities or at least two regions of a single cavity, wherein the regions contain different types of particles.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: January 11, 2011
    Assignee: Board of Regents of the University of Nebraska
    Inventors: Dennis R. Alexander, John C. Bruce, III, Craig A. Zuhlke, Brandon E. Koch, Jitender S. Deogun, Haitham S. Hamza
  • Publication number: 20110001966
    Abstract: Systems and methods are provided for monitoring materials using ultra fast laser pulses. Ultra fast laser pulses, such as femtosecond or attosecond laser pulses, are applied to the materials and laser pulses that result from interactions between the ultra fast laser pulses and the materials are collected. Spectral content of the resulting pulses is generated and presented. The elemental composition of the materials is determined using the spectral content.
    Type: Application
    Filed: November 2, 2007
    Publication date: January 6, 2011
    Applicant: BOARD OF REGENTS OF THE UNIVERSITY OF NEBRASKA
    Inventor: DENNIS R. ALEXANDER
  • Publication number: 20100065756
    Abstract: A particle based optical diode having at least two cavities or at least two regions of a single cavity, wherein the regions contain different types of particles.
    Type: Application
    Filed: January 23, 2006
    Publication date: March 18, 2010
    Applicant: Board of Regents of University of Nebraska
    Inventors: Dennis R. Alexander, John C. Bruce, III, Craig A. Zuhlke, Brandon E. Koch, Jitender S. Deogun, Haitham S. Hamza
  • Publication number: 20080296263
    Abstract: Disclosed are systems and methods for directing laser energy to surfaces of materials via elements which have sharp points, and for reducing the adverse effects of particles which become dislodged by scribing and laser machining of materials.
    Type: Application
    Filed: June 30, 2008
    Publication date: December 4, 2008
    Applicant: BOARD OF REGENTS OF UNIVERSITY OF NEBRASKA
    Inventors: DENNIS R. ALEXANDER, JOHN BRUCE, III
  • Patent number: 6864457
    Abstract: Disclosed are systems and methods for reducing the adverse effects of particles which become dislodged by scribing and laser machining of materials, which dislodged particles otherwise accumulate on laser machined material surfaces and cause adverse effects.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: March 8, 2005
    Assignee: The Board of Regents of the University of Nebraska
    Inventors: Dennis R. Alexander, Brian W. Milulka, David W. Doerr
  • Patent number: 6583911
    Abstract: A free-space optical communications system is provided capable of transmitting data over long distances through the atmosphere. The communications system according to the present invention comprises an optical transmitter at a first location, the optical transmitter comprising a femtosecond pulsed laser source for producing a train of femtosecond laser pulses. The optical transmitter further comprises a laser pulse width modulator to provide a pulse width modulated train of femtosecond laser pulses corresponding to the data being transmitted. The communications system further comprises an optical receiver at a second location for receiving the modulated train of femtosecond laser pulses. The optical receiver comprises a spectral analyzer for detecting the spectral components of the pulse width modulated train of femtosecond laser pulses.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: June 24, 2003
    Inventors: Dennis R. Alexander, Mark L. Rohlfs
  • Patent number: 6489589
    Abstract: The present invention teaches various femtosecond machining and drilling apparatus and processes for fabricating tools and the like from both traditional and non-traditional materials. Also described are novel tools such as scalpels, and nozzles fabricated from the apparatus and processes of the present invention. Likewise, the present invention may be utilized in both a novel propulsion system and the production of materials formed from nanometer sized particles and the like.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: December 3, 2002
    Assignee: Board of Regents, University of Nebraska-Lincoln
    Inventor: Dennis R. Alexander
  • Patent number: 5847825
    Abstract: A method and apparatus for in situ detection and concentration measurement of trace elements in an analysis sample is disclosed. The invention uses laser induced breakdown spectroscopy (LIBS) wherein femtosecond pulsed laser energy is employed to produce the plasma. The femtosecond pulsed laser energy is focused on the analysis sample to produce the plasma and the resulting emission is delivered for spectral analysis. Because the method and apparatus of the present invention allow breakdown of the analysis sample without propagation of energy to the sample-air interface, a plasma is produced that consists essentially of sample materials without being contaminated by air plasma formation. Thus, the background emission is reduced and there is no need to wait for the plasma to cool down over time before detecting the spectral lines of the sample. Because there is no need to wait for cooling before spectral measurement, lower detection limits are possible.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: December 8, 1998
    Assignee: Board of Regents University of Nebraska Lincoln
    Inventor: Dennis R. Alexander
  • Patent number: 5586714
    Abstract: A method of bonding metal to a non-metal substrate. The process includes placing the metal in contact with a non-metal substrate and blanketing the contact region with a gaseous atmosphere in which the amount of reactive gas is limited to minimize oxidation of the metal at the surface. Heating of the metal is accomplished by various means including a laser beam. The metal is heated to a point where the reactive gas and metal form a eutectic that wets the contact area between the metal and non-metallic substrate. Upon cooling, the metal and non-metallic substrate are bonded together over a substantial part of the contact area.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: December 24, 1996
    Assignee: Board of Regents of the University of Nebraska
    Inventors: Victor Curicuta, Dennis R. Alexander, Robert J. Deangelis, Brian W. Robertson
  • Patent number: 5553791
    Abstract: To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to supply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: September 10, 1996
    Assignee: The Board of Regents of the University of Nebraska
    Inventor: Dennis R. Alexander
  • Patent number: 5390864
    Abstract: To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to supply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.
    Type: Grant
    Filed: January 4, 1993
    Date of Patent: February 21, 1995
    Assignee: The Board of Regents of the University of Nebraska
    Inventor: Dennis R. Alexander
  • Patent number: 5176328
    Abstract: To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to supply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.
    Type: Grant
    Filed: June 10, 1991
    Date of Patent: January 5, 1993
    Assignee: The Board of Regents of the University of Nebraska
    Inventor: Dennis R. Alexander
  • Patent number: 5044565
    Abstract: To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to suply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.
    Type: Grant
    Filed: March 13, 1990
    Date of Patent: September 3, 1991
    Assignee: The Board of Regents of the University of Nebrasaka
    Inventor: Dennis R. Alexander