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).
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Publication number: 20240139865Abstract: A method for laser-processing a metallic surface to produce a functionalized metallic surface comprises: providing a material substrate having the surface; and applying a pulsed laser beam to a region of the surface, the pulsed laser beam being applied at a non-normal angle to the surface, wherein material in the region of the surface ablates due to the applied pulsed laser beam and wherein at least a portion of the ablated material redeposits on the surface to produce one or more material-coated structures angled at the non-normal angle with respect to the surface, wherein the surface having the one or more material-coated structures is the functionalized surface. The functionalized metallic surface has broadband directional emissivity independent of polarization.Type: ApplicationFiled: August 3, 2023Publication date: May 2, 2024Inventors: Craig Zuhlke, Andrew Reicks, Christos Argyropoulos, Andrew Butler, George Gogos, Dennis R. Alexander
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Publication number: 20220161365Abstract: Aspects and embodiments disclosed herein include a method for forming a plurality of microfeatures, the method comprising: irradiating a starting multi-layer material with a pulsed laser beam at a plurality of locations of the multi-layer material; wherein: the starting multi-layer material comprises a plurality of starting layers comprising a first starting layer having a first composition and a second starting layer adjacent to the first starting layer and having a second composition different than the first composition; the plurality of microfeatures form in the multi-layer starting material during the step of irradiating; each microfeature comprises a plurality of microfeature layers comprising a first microfeature layer having the first composition and a second microfeature layer having the second composition. Optionally, each of the first and second composition is an inorganic material.Type: ApplicationFiled: May 28, 2021Publication date: May 26, 2022Inventors: Alfred T. TSUBAKI, Dennis R. ALEXANDER, Craig ZUHLKE, Jeffrey SHIELD, Mark ANDERSON, Andrew REICKS
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Publication number: 20220143748Abstract: A method for laser-processing a metallic surface to produce a functionalized metallic surface comprises: providing a substrate having the metallic surface; applying a pulsed laser beam with a controlled fluence to a region of the metallic surface in an environment containing oxygen, wherein metal material in the region of the metallic surface ablates due to the applied pulsed laser beam and wherein at least a portion of the ablated metal material oxidizes and redeposits on the metallic surface to produce one or more oxidized-metal-coated structures; wherein the metallic surface having the one or more oxidized-metal-coated structures is the functionalized metallic surface. Optionally, the functionalized metallic surface has a higher hemispherical emissivity than the metallic surface free of the oxidized-metal-coated structures and prior to applying the pulsed laser beam under otherwise identical conditions.Type: ApplicationFiled: November 12, 2021Publication date: May 12, 2022Inventors: Andrew R. Reicks, Craig Zuhlke, Alfred Tooru Tsubaki, Christos Argyropoulos, George Gogos, Mark Anderson, Dennis R. Alexander
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Publication number: 20120314214Abstract: 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: ApplicationFiled: June 7, 2012Publication date: December 13, 2012Inventors: DENNIS R. ALEXANDER, TROY ANDERSON, JOHN C. BRUCE, III
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Patent number: 8247731Abstract: 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: GrantFiled: June 30, 2008Date of Patent: August 21, 2012Assignee: Board of Regents of the University of NebraskaInventors: Dennis R. Alexander, John Bruce, III
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Patent number: 8189190Abstract: 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: GrantFiled: November 2, 2007Date of Patent: May 29, 2012Assignee: Board of Regents of the University of NebraskaInventor: Dennis R. Alexander
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Patent number: 7868302Abstract: 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: GrantFiled: January 23, 2006Date of Patent: January 11, 2011Assignee: Board of Regents of the University of NebraskaInventors: Dennis R. Alexander, John C. Bruce, III, Craig A. Zuhlke, Brandon E. Koch, Jitender S. Deogun, Haitham S. Hamza
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Publication number: 20110001966Abstract: 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: ApplicationFiled: November 2, 2007Publication date: January 6, 2011Applicant: BOARD OF REGENTS OF THE UNIVERSITY OF NEBRASKAInventor: DENNIS R. ALEXANDER
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Publication number: 20100065756Abstract: 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: ApplicationFiled: January 23, 2006Publication date: March 18, 2010Applicant: Board of Regents of University of NebraskaInventors: Dennis R. Alexander, John C. Bruce, III, Craig A. Zuhlke, Brandon E. Koch, Jitender S. Deogun, Haitham S. Hamza
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Publication number: 20080296263Abstract: 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: ApplicationFiled: June 30, 2008Publication date: December 4, 2008Applicant: BOARD OF REGENTS OF UNIVERSITY OF NEBRASKAInventors: DENNIS R. ALEXANDER, JOHN BRUCE, III
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Patent number: 6864457Abstract: 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: GrantFiled: January 21, 2003Date of Patent: March 8, 2005Assignee: The Board of Regents of the University of NebraskaInventors: Dennis R. Alexander, Brian W. Milulka, David W. Doerr
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Patent number: 6583911Abstract: 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: GrantFiled: October 6, 2000Date of Patent: June 24, 2003Inventors: Dennis R. Alexander, Mark L. Rohlfs
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Patent number: 6489589Abstract: 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: GrantFiled: March 5, 1998Date of Patent: December 3, 2002Assignee: Board of Regents, University of Nebraska-LincolnInventor: Dennis R. Alexander
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Patent number: 5847825Abstract: 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: GrantFiled: September 25, 1997Date of Patent: December 8, 1998Assignee: Board of Regents University of Nebraska LincolnInventor: Dennis R. Alexander
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Patent number: 5586714Abstract: 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: GrantFiled: October 6, 1994Date of Patent: December 24, 1996Assignee: Board of Regents of the University of NebraskaInventors: Victor Curicuta, Dennis R. Alexander, Robert J. Deangelis, Brian W. Robertson
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Patent number: 5553791Abstract: 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: GrantFiled: February 21, 1995Date of Patent: September 10, 1996Assignee: The Board of Regents of the University of NebraskaInventor: Dennis R. Alexander
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Patent number: 5390864Abstract: 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: GrantFiled: January 4, 1993Date of Patent: February 21, 1995Assignee: The Board of Regents of the University of NebraskaInventor: Dennis R. Alexander
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Patent number: 5176328Abstract: 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: GrantFiled: June 10, 1991Date of Patent: January 5, 1993Assignee: The Board of Regents of the University of NebraskaInventor: Dennis R. Alexander
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Patent number: 5044565Abstract: 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: GrantFiled: March 13, 1990Date of Patent: September 3, 1991Assignee: The Board of Regents of the University of NebrasakaInventor: Dennis R. Alexander