Patents by Inventor James J. Coleman
James J. Coleman 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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Patent number: 8494025Abstract: A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide guides emission. The waveguide includes a broad area straight coupling region that fans out into an array of narrower Individual curved coupled waveguides at an output facet of the laser. The individual curved coupled waveguides are curved according to Lorentzian functions that define the waveguide curvature as a function of position along the device. The integral length of each individual curved coupled waveguide differs from adjacent individual curved coupled waveguides by an odd number of half-wavelengths. The coupled waveguide array shapes the optical field output of the semiconductor laser such that a large fraction of the power is emitted into a small angular distribution using interference phenomena. A laser of the invention produces high power output with a very high quality, narrow beam shape.Type: GrantFiled: May 7, 2008Date of Patent: July 23, 2013Assignee: The Board of Trustees of the Univeristy of IllinoisInventors: James J. Coleman, Victor C. Elarde
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Patent number: 8416823Abstract: The invention provides a quantum well active region for an optoelectronic device. The quantum well active region includes barrier layers of high bandgap material. A quantum well of low bandgap material is between the barrier layers. Three-dimensional high bandgap barriers are in the quantum well. A preferred semiconductor laser of the invention includes a quantum well active region of the invention. Cladding layers are around the quantum well active region, as well as a waveguide structure.Type: GrantFiled: April 29, 2008Date of Patent: April 9, 2013Assignee: The Board of Trustees of the University of IllinoisInventors: James J. Coleman, Victor C. Elarde
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Patent number: 8222988Abstract: A porous device for optical and electronic applications comprises a single crystal substrate and a porous single crystal structure epitaxially disposed on the substrate, where the porous single crystal structure includes a three-dimensional arrangement of pores. The three-dimensional arrangement may also be a periodic arrangement. A method of fabricating such a device includes forming a scaffold comprising interconnected elements on a single crystal substrate, where the interconnected elements are separated by voids. A first material is grown epitaxially on the substrate and into the voids. The scaffold is then removed to obtain a porous single crystal structure epitaxially disposed on the substrate, where the single crystal structure comprises the first material and includes pores defined by the interconnected elements of the scaffold.Type: GrantFiled: July 30, 2009Date of Patent: July 17, 2012Assignee: The Board of Trustees of the University of IllinoisInventors: Paul V. Braun, James J. Coleman, Victor C. Elarde, Erik C. Nelson, Varun B. Verma
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Publication number: 20100208761Abstract: The invention provides a quantum well active region for an optoelectronic device. The quantum well active region includes barrier layers of high bandgap material. A quantum well of low bandgap material is between the barrier layers. Three-dimensional high bandgap barriers are in the quantum well. A preferred semiconductor laser of the invention includes a quantum well active region of the invention. Cladding layers are around the quantum well active region, as well as a waveguide structure.Type: ApplicationFiled: April 29, 2008Publication date: August 19, 2010Applicant: The Board of Trustees of The University of IllnoisInventors: James J. Coleman, Victor C. Elarde
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Publication number: 20100195683Abstract: A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide guides emission. The waveguide includes a broad area straight coupling region that fans out into an array of narrower Individual curved coupled waveguides at an output facet of the laser. The individual curved coupled waveguides are curved according to Lorentzian functions that define the waveguide curvature as a function of position along the device. The integral length of each individual curved coupled waveguide differs from adjacent individual curved coupled waveguides by an odd number of half- wavelengths. The coupled waveguide array shapes the optical field output of the semiconductor laser such that a large fraction of the power is emitted into a small angular distribution using interference phenomena. A laser of the invention produces high power output with a very high quality, narrow beam shape.Type: ApplicationFiled: May 7, 2008Publication date: August 5, 2010Applicant: The Board of Trustees of the University of IllinoisInventors: James J. Coleman, Victor C. Elarde
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Publication number: 20100065889Abstract: A porous device for optical and electronic applications comprises a single crystal substrate and a porous single crystal structure epitaxially disposed on the substrate, where the porous single crystal structure includes a three-dimensional arrangement of pores. The three-dimensional arrangement may also be a periodic arrangement. A method of fabricating such a device includes forming a scaffold comprising interconnected elements on a single crystal substrate, where the interconnected elements are separated by voids. A first material is grown epitaxially on the substrate and into the voids. The scaffold is then removed to obtain a porous single crystal structure epitaxially disposed on the substrate, where the single crystal structure comprises the first material and includes pores defined by the interconnected elements of the scaffold.Type: ApplicationFiled: July 30, 2009Publication date: March 18, 2010Inventors: Paul V. Braun, James J. Coleman, Victor C. Elarde, Erik C. Nelson, Varun B. Verma
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Patent number: 7339968Abstract: Dual-wavelength operation is easily achieved by biasing the gain section. Multiple gratings spaced apart from each other are separated from an output aperture by a gain section. A relatively low coupling coefficient, ?, in the front grating reduces the added cavity loss for the back grating mode. Therefore, the back grating mode reaches threshold easily. The space section lowers the current induced thermal interaction between the two uniform grating sections, significantly reducing the inadvertent wavelength drift. As a result, a tunable mode pair separations (??) as small as 0.3 nm and as large as 6.9 nm can be achieved.Type: GrantFiled: February 13, 2004Date of Patent: March 4, 2008Assignee: The Board of Trustees of the University of IllinoisInventors: James J. Coleman, S. David Roh
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Patent number: 6728290Abstract: A laser heterostructure having an active layer, a lateral waveguide terminating in an output aperture, and a gain section with a current drive electrode. A rear surface distributed Bragg grating with a tuning current electrode is formed on a surface of said laser heterostructure. The laser also includes a front surface distributed Bragg grating with a tuning current electrode on a surface of the laser heterostructure. The front surface distributed Bragg grating is closer to the output aperture than the rear surface distributed Bragg grating, There is a space between the rear surface distributed Bragg grating and the front surface distributed Bragg grating. A current drive electrode is formed on the space. Operation is best when the front surface distributed Bragg grating has adequate reflectivity at the Bragg wavelength with minimal scattering loss at other wavelengths, particularly at the wavelength of the rear surface Bragg grating.Type: GrantFiled: September 13, 2000Date of Patent: April 27, 2004Assignee: The Board of Trustees of the University of IllinoisInventors: James J. Coleman, S. David Roh
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Publication number: 20030219053Abstract: An index guide laser structure of the invention utilizes the combination of two spatial filter elements to limit or eliminate oscillation of high order lateral modes and beam steering. A preferred structure utilizes a frustrated and curved index guide to induce bend loss in higher order modes, and another preferred structure utilizes frustrating guides to introduce periodic interruptions of the refractive index outside the central guide to induce scattering loss in the higher order modes.Type: ApplicationFiled: February 19, 2003Publication date: November 27, 2003Applicant: The Board of Trustees of the University of IllinoisInventors: Reuel B. Swint, James J. Coleman, Mark Zediker
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Patent number: 6649940Abstract: A semiconductor quantum well laser having separate lateral confinement of injected carriers and the optical mode. A ridge waveguide is used to confine the optical mode. A buried heterostructure confines injected carriers. A preferred embodiment laser of the invention is a layered semiconductor structure including optical confinement layers. A buried heterojunction quantum well within the optical confinement layers is dimensioned and arranged to confine injected carriers during laser operation. A ridge waveguide outside the optical confinement layers is dimensioned and arranged with respect to the buried heterojunction to confine an optical mode during laser operation. An index step created by the buried heterojunction is substantially removed from the optical mode.Type: GrantFiled: June 29, 2001Date of Patent: November 18, 2003Assignees: The Board of Trustees of the University of Illinois, Nuvonyx, Inc.Inventors: James J. Coleman, Reuel B. Swint, Mark S. Zediker
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Publication number: 20030006408Abstract: A semiconductor quantum well laser having separate lateral confinement of injected carriers and the optical mode. A ridge waveguide is used to confine the optical mode. A buried heterostructure confines injected carriers. A preferred embodiment laser of the invention is a layered semiconductor structure including optical confinement layers. A buried heterojunction quantum well within the optical confinement layers is dimensioned and arranged to confine injected carriers during laser operation. A ridge waveguide outside the optical confinement layers is dimensioned and arranged with respect to the buried heterojunction to confine an optical mode during laser operation. An index step created by the buried heterojunction is substantially removed from the optical mode.Type: ApplicationFiled: June 29, 2001Publication date: January 9, 2003Inventors: James J. Coleman, Reuel B. Swint, Mark S. Zediker
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Patent number: 6317445Abstract: A semiconductor laser structure based upon a rib waveguide geometry which includes a uniform region and a flared and tapered region. The uniform region has a generally constant thickness and width. The flared tapered region gradually increases in width and decreases in thickness from the uniform region to a wide end. Fabrication is by selective area epitaxy with dielectric stripes in a dual stripe dielectric mask used to defined the two dimensional varying flare in the waveguide changing in thickness as a function of the flare width.Type: GrantFiled: April 11, 2000Date of Patent: November 13, 2001Assignee: The Board of Trustees of the University of IllinoisInventors: James J. Coleman, Mark S. Zediker
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Patent number: 4994882Abstract: A semiconductor heterostructure device is disclosed which includes a first semiconductor layer having a barrier layer disposed thereon, the barrier layer being formed of a semiconductor material having a wider bandgap than the material of the first semiconductor layer. A carrier transport layer is disposed on the barrier layer, the carrier transport layer being formed of a semiconductor material having a narrower bandgap than the material of the barrier layer. A contact layer is disposed on the carrier transport layer. A negative potential is applied to the contact layer with respect to the first semiconductor layer. In operation, for small voltages, under the indicated bias configuration, electrons supplied to the carrier transport layer by the source of negative potential supply will be blocked at the barrier presented by the larger bandgap barrier layer, and little current will flow.Type: GrantFiled: February 10, 1989Date of Patent: February 19, 1991Assignee: University of IllinoisInventors: Karl Hess, James J. Coleman, Ted K. Higman, Mark A. Emanuel
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Patent number: 4517674Abstract: A zinc-diffused narrow stripe AlGaAs/GaAs double heterostructure laser device and a method of making the same. A double heterostructure layered structure including a p-type GaAs active layer sandwiched between two n-type AlGaAs confinement layers is formed on a substrate. A p-type zinc diffused stripe region having a U-shaped diffusion front extends longitudinally between two reflective surfaces located on respective ends of the device and extends vertically from the surface of the upper confinement layer down to at least the surface of intersection between the active layer and the lower confinement layer. In a method of forming the device, the various layers are formed by epitaxial growth or by metalorganic chemical vapor deposition. The stripe region is formed by diffusing zinc from a source through a slot in a diffusion mask. The zinc diffused into the device is driven in by heating the device in the absence of the zinc source.Type: GrantFiled: August 31, 1982Date of Patent: May 14, 1985Assignee: The United States of America as represented by the Secretary of the NavyInventors: Yet-Zen Liu, Chi-Shain Hong, P. Danial Dapkus, James J. Coleman
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Patent number: 4144634Abstract: A method of fabricating gallium arsenide MOS devices with improved stoichiometric and electrical properties is disclosed. The device includes a gallium arsenide substrate overlaid with a native oxide and an aluminum oxide layer. The device is fabricated using a plasma oxidizing process.Type: GrantFiled: June 28, 1977Date of Patent: March 20, 1979Assignee: Bell Telephone Laboratories, IncorporatedInventors: Chuan C. Chang, Robert P. H. Chang, James J. Coleman, Tan T. Sheng