Patents by Inventor Thomas F. Johnston, Jr.
Thomas F. Johnston, Jr. 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: 7147654Abstract: A method and apparatus for treating skin disorders includes a source of pulsed near black body electromagnetic energy and a means of delivering this energy to a treatment site. A means for cooling the treatment site is described. The number of pulses and intensity of the energy can be varied. Optical filters are used to limit the spectrum of energy emitted and the filters are cooled to allow high-energy operation. The size of the treatment spot is controlled by a series of apertures.Type: GrantFiled: January 24, 2003Date of Patent: December 12, 2006Assignee: LaserscopeInventors: Jonathan M. Baumgardner, David R. Hennings, Thomas F. Johnston, Jr., B. Eric Taylor, Mitchell P. Goldman
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Patent number: 5267012Abstract: A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife edges 40,42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.Type: GrantFiled: February 5, 1993Date of Patent: November 30, 1993Assignee: Coherent, Inc.Inventors: Michael W. Sasnett, Thomas F. Johnston, Jr.
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Patent number: 5214485Abstract: A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife edges (40,42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.Type: GrantFiled: January 24, 1992Date of Patent: May 25, 1993Assignee: Coherent, Inc.Inventors: Michael W. Sasnett, Thomas F. Johnston, Jr.
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Patent number: 5100231Abstract: A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife edges (40,42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.Type: GrantFiled: April 27, 1989Date of Patent: March 31, 1992Assignee: Coherent, Inc.Inventors: Michael W. Sasnett, Thomas F. Johnston, Jr.
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Patent number: 5078491Abstract: A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife edges (40,42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.Type: GrantFiled: April 26, 1990Date of Patent: January 7, 1992Assignee: Coherent, Inc.Inventor: Thomas F. Johnston, Jr.
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Patent number: 5069527Abstract: A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (34) having apertures (36, 38) for seletively passing the beam. Preferably, one of the appertures has a pair of 45.degree. knife edges (40, 42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.Type: GrantFiled: April 26, 1990Date of Patent: December 3, 1991Assignee: Coherent, Inc.Inventors: Thomas F. Johnston, Jr., David A. Dewey
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Patent number: 5064284Abstract: A method and apparatus for determining the quality of a multimode laser beam (10). In the preferred embodiment, the apparatus includes a lens (32) for creating a transformed or imaged waist from the input beam. The location of the transformed beam waist and its diameter are then determined. These steps can be carried out by chopping the beam using a rotating hub (14) having apertures (36,38) for selectively passing the beam. Preferably, one of the apertures has a pair of 45.degree. knife edges (40,42). The transmission of the beam past the knife edge is monitored by a detector (30). In operation, the lens focal position is varied while the transmission of the beam past the knife edge is monitored in order to locate and measure the diameter of the transformed waist. The diameter of the beam at one other known location is measured. A processor then calculates beam quality by fitting these measurements to a mathematical model.Type: GrantFiled: April 26, 1990Date of Patent: November 12, 1991Assignee: Coherent, Inc.Inventors: Thomas F. Johnston, Jr., Gerald H. Williams
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Patent number: 4514849Abstract: A laser-pumped laser system is disclosed, such as a dye laser which is optically pumped by an argon ion laser. An improved servo system is provided for maintaining relative alignment of the pump laser beam with respect to the dye laser cavity. This is accomplished by rotating the pump beam such that the beam defines a conical surface, by means such as an optically-transmissive rotating wedge. Such rotation provides dithering along two orthogonal axes, which provides the necessary control information to maintain pump beam alignment.Type: GrantFiled: September 7, 1983Date of Patent: April 30, 1985Assignee: Coherent, Inc.Inventors: Kenneth G. Witte, Thomas F. Johnston, Jr.
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Patent number: 4272158Abstract: A broadband optical diode consists of a Faraday element within a magnetic field and an optically active element. The materials and dimensions of the Faraday element and the optically active element are chosen so that their polarization rotations approximately match over a broad wavelength span, with the rotation angles and the mismatch between them specified by the conditions that the forward wave insertion loss does not exceed a maximum specified value, and the differential loss between forward and backward traveling waves is not less than a minimum specified value.Type: GrantFiled: March 2, 1979Date of Patent: June 9, 1981Assignee: Coherent, Inc.Inventors: Thomas F. Johnston, Jr., William P. Proffitt
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Patent number: 4268800Abstract: A tipping Brewster plate, used for fine tuning a tunable ring laser, such as a dye laser, is located close to a flat mirror comprising one of the optical elements of the ring optical resonator, so that both the incident and reflected beam from the flat mirror pass through the tipping Brewster plate. When the ring laser is tuned by tipping the Brewster plate, no lateral displacement of the ring laser beam takes place.Type: GrantFiled: April 30, 1979Date of Patent: May 19, 1981Assignee: Coherent, Inc.Inventors: Thomas F. Johnston, Jr., William P. Proffitt
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Patent number: 4150342Abstract: Method and apparatus are disclosed in a frequency controlled tunable laser system which may be tuned selectively by an operator to any predetermined output radiation frequency within its operating range and servo-locked to maintain that output frequency, for rapidly and automatically maintaining and reacquiring a predetermined output radiation frequency despite momentary interruptions or perturbations of laser oscillation.Type: GrantFiled: July 5, 1977Date of Patent: April 17, 1979Assignee: Coherent, Inc.Inventors: Thomas F. Johnston, Jr., James L. Hobart, Robert C. Rempel, Gerald H. Williams