Short Wavelength Laser Patents (Class 372/5)
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Publication number: 20020097767Abstract: Disclosed is a gas laser utilizing radio frequency excitation in the area of sonic or supersonic/subsonic transfer gas flow. The laser uses various types of gases and mixtures of gases as the active medium using radio frequency excitation. The gas is supplied into a supersonic nozzle for acceleration of the active gaseous flow to supersonic or deceleration to high subsonic speeds in order to provide intensive dynamic cooling of the active gas medium. The gas is excited using radio frequency excitation in the critical area of the supersonic nozzle or downstream therefrom. The radio frequency action and excitation can also occur within the optical resonator region which is located within the supersonic area of the nozzle.Type: ApplicationFiled: March 5, 2001Publication date: July 25, 2002Inventor: Alexander V. Krasnov
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Publication number: 20020061033Abstract: It is an object of the present invention to provide a short-wavelength coherent light source that includes a semiconductor laser and a wavelength converting device and is controlled to have a desired wavelength. The coherent light source includes the following: a semiconductor laser having a first wavelength; an optical waveguide-type QPM-SHG device used as a wavelength converting device for converting the wavelength of the semiconductor laser by half; a wavelength separating function; a diffraction grating; and a photo-detector. The semiconductor laser beam acting as fundamental light is separated with the wavelength separating function, and the wavelength is controlled with the diffraction grating. Thus, the wavelength of harmonic light generated by wavelength conversion is controlled to a desired wavelength.Type: ApplicationFiled: October 24, 2001Publication date: May 23, 2002Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Yasuo Kitaoka, Ken?apos;ichi Kasazumi, Kazuhisa Yamamoto
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Patent number: 6385223Abstract: A method for connecting an optical waveguide and an optical semiconductor device and an apparatus for connecting the same, capable of removing a working error and getting a high optical coupling coefficiency.Type: GrantFiled: February 7, 2000Date of Patent: May 7, 2002Assignee: NEC CorporationInventor: Mitsuru Kurihara
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Patent number: 6373869Abstract: An optical system for producing ultraviolet radiation includes an optical source, an optical parametric oscillator (OPO), a frequency doubler, and a mixer. The optical source produces a first beam of radiation. The OPO receives a first portion of the first beam of radiation and produces a second beam of radiation therefrom. The frequency doubler receives a second portion of the first beam of radiation and produces the second harmonic thereof. The mixer mixes the second beam of radiation and the second harmonic of the first beam of radiation to produce an ultraviolet beam of radiation. In a preferred embodiment, the optical source includes a Nd:YAG laser which is frequency doubled to produce a first beam of radiation at a wavelength of approximately 532 nm; and the ultraviolet beam of radiation has a wavelength close to one of the excimer laser lines, typically either 193 nm or 157 nm.Type: GrantFiled: July 29, 1999Date of Patent: April 16, 2002Assignee: ActinixInventor: James J. Jacob
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Publication number: 20020034198Abstract: Provided is a small-sized laser light generating apparatus capable of oscillating continuous light with a range of wavelengths of about 200 nm or less with stability at high conversion efficiency. Light with wavelength &lgr;1 and light with wavelength &lgr;2 outputted from a first laser light generator and a second laser light generator are introduced into a first resonator and a second resonator, respectively, and then a nonlinear optical device included in both the first and second resonators generates light with wavelength &lgr;3 through sum-frequency mixing of these two incoming light beams. The light with the wavelength &lgr;1, the light with the wavelength &lgr;2 and the light with the wavelength &lgr;3, which are spatially separated from one another, enter into and exit from the nonlinear optical device and have different optical paths.Type: ApplicationFiled: September 19, 2001Publication date: March 21, 2002Inventor: Hisashi Masuda
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Patent number: 6356570Abstract: A source of intense coherent high-frequency electromagnetic radiation such as soft x-rays. A circularly polarized incident beam of coherent radiation is directed at a frequency multiplication medium that includes constituents of approximate Cn symmetry, oriented so that the symmetry axes of the constituents are parallel to the incident beam. The interaction of the incident beam and the constituents of the medium produces higher harmonics of the incident frequency, up into the x-ray band. If the Cn symmetry of the medium constituents is exact then the harmonic frequencies are multiples ln±l of the frequency of the incident beam, where l is an integer. If the Cn symmetry is only approximate, then the harmonics are centered around these multiples. Suitable medium constituents include dipolar molecules of C5v symmetry and circular rings of nanoparticles.Type: GrantFiled: August 11, 2000Date of Patent: March 12, 2002Assignee: Technion Research and Development Foundation LTDInventors: Ofir Alon, Vitali Averbukh, Nimrod Moiseyev
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Patent number: 6356618Abstract: An extreme ultraviolet and soft x-ray radiation electric capillary discharge source that includes a boron nitride housing defining a capillary bore that is positioned between two electrodes one of which is connected to a source of electric potential can generate a high EUV and soft x-ray radiation flux from the capillary bore outlet with minimal debris. The electrode that is positioned adjacent the capillary bore outlet is typically grounded. Pyrolytic boron nitride, highly oriented pyrolytic boron nitride, and cubic boron nitride are particularly suited. The boron nitride capillary bore can be configured as an insert that is encased in an exterior housing that is constructed of a thermally conductive material. Positioning the ground electrode sufficiently close to the capillary bore outlet also reduces bore erosion.Type: GrantFiled: June 13, 2000Date of Patent: March 12, 2002Assignee: EUV LLCInventors: Neal R. Fornaciari, Richard E. Nygren, Michael A. Ulrickson
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Patent number: 6347100Abstract: A fiber laser uses a mechanism to prevent a thermally induced shift of the gain spectrum to a range that causes the laser to become destabilized when operated at a first signal wavelength. By establishing a nominal gain spectrum that is further from the undesired range than in a conventional laser, a gain spectrum shift does not reach the undesired wavelength range. This may be accomplished by decreasing the reflectivity of a resonant cavity of the laser, such as by angling the reflective end of the cavity. It may also be accomplished by increasing the population inversion of the laser. Using a pump energy reflector to prevent pump energy from exiting the inner cladding of a double-clad version of the laser the fiber may increase population inversion. The fiber length may also be shortened or the diameter of the inner cladding reduced to increase the population inversion before a laser output is achieved.Type: GrantFiled: October 15, 1999Date of Patent: February 12, 2002Assignee: SDL, Inc.Inventors: Steven Sanders, Bernard G. Fidric
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Patent number: 6343089Abstract: A microwave-driven ultraviolet (UV) light source is provided. The light source comprises an over-moded microwave cavity having at least one discharge bulb disposed within the microwave cavity. At least one magnetron probe is coupled directly to the microwave cavity.Type: GrantFiled: August 25, 1999Date of Patent: January 29, 2002Assignee: College of William & MaryInventors: Dennis M. Manos, Jessie Diggs, Joseph D. Ametepe
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Patent number: 6327284Abstract: An ultraviolet light detection system is provided wherein a dark current background growth rate with total accumulated exposure dose is avoided, and parameters of an ultraviolet radiation source such as an ArF-excimer laser may be monitored without rapid degradation of the signal by the superposition of the dark current background over a desired signal. The invention provides a detector including a light sensitive element having a frequency conversion coating on its surface. The coating is preferably directly on the light sensitive element, absorbing incident ultraviolet light and re-emitting visible light in a direction toward the light sensitive element. The coating minimizes a dark current background that would otherwise appear when incident ultraviolet light impinges directly upon the light sensitive element, and thereby extends a lifetime of the light sensitive element.Type: GrantFiled: October 14, 1998Date of Patent: December 4, 2001Assignee: Lambda Physik AGInventors: Uwe Stamm, Hans-Stephan Albrecht, Uwe Leinhos, Wolfgang Zschocke
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Patent number: 6275512Abstract: A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.Type: GrantFiled: November 25, 1998Date of Patent: August 14, 2001Assignee: Imra America, Inc.Inventor: Martin E. Fermann
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Patent number: 6275514Abstract: Apparatus for producing high repetition rate optical pulses, including: a beam generator that produces an initial pulsed light beam having an initial pulse repetition rate; a pulse repetition rate multiplier, which receives the initial pulsed light beam and produces at least one pulsed light beam having a higher pulse repetition rate than the initial rate.Type: GrantFiled: November 19, 1998Date of Patent: August 14, 2001Assignee: Orbotech Ltd.Inventors: Yigal Katzir, Boris Kling, Paul Fenster, Avraham Gross
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Patent number: 6208673Abstract: A method and apparatus for obtaining multiple wavelengths of varying temporal format from a single solid state laser are provided. Accordingly, the output from the solid state laser can either be sent through a series of non-linear crystals to obtain UV radiation or through an OPO cavity to obtain IR radiation. In order to provide the different wavelengths in the temporal formats commonly used for various medical procedures, the laser source may be operated in two different modes. When the laser system produces UV radiation a pulse of short duration is desired and the laser source is operated in the standard Q-switched mode or is mode locked. Conversely, when the laser system produces IR radiation, a pulse of long duration is desired and the laser source is operated in the free running mode.Type: GrantFiled: May 21, 1999Date of Patent: March 27, 2001Assignee: Aculight CorporationInventor: Charles I. Miyake
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Patent number: 6185232Abstract: An optical transmitter (405) includes a distributed feedback semiconductor laser (100) operated in a linear regime below a threshold associated with stimulated Brillouin scattering to generate an optical signal. A resistor (125) or other heater is physically coupled to the semiconductor laser (100), and a modulated current source (120) drives the resistor (125) with a triangle waveform (300), thereby varying an optical wavelength of the optical signal such that the optical signal and a double Rayleigh backscattered signal are characterized, at the optical receiver (410), by different optical frequencies. As a result, interference generated by Rayleigh backscattering is minimized at the optical receiver (410).Type: GrantFiled: June 30, 1998Date of Patent: February 6, 2001Assignee: Scientific-Atlanta, Inc.Inventors: Doren W. Hess, Jr., Rezin E. Pidgeon, Jr.
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Patent number: 6167065Abstract: An extremely compact soft x-ray and/or extreme ultraviolet laser is disclosed that can be repetitively fired within short time intervals. The laser generates a plasma within a capillary (3) by flowing through the capillary (3) a fast high current pulse generated by a very compact liquid dielectric (1) transmission line (9) geometry.Type: GrantFiled: April 29, 1999Date of Patent: December 26, 2000Assignee: Colorado State University Research FoundationInventor: Jorge Rocca
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Patent number: 6137821Abstract: A durable etalon based laser output coupler. The output coupler is especially useful for ultraviolet lasers such as an ArF excimer laser or an F.sub.2 laser. The principal elements of the etalon based output coupler are two prisms aligned so that a first surface of one of the two prisms is parallel to a first surface of the other prism. The first of the two prisms have a second surface forming an angle with a beam from a laser cavity equal to or approximately equal to Brewster's angle. The second of the two prisms has a second surface forming an angle with the coupler exit beam equal to or approximately equal to Brewster's angle. Preferably, the prisms are comprised of CaF.sub.2 and surrounded by nitrogen at about one atmosphere. Assuming the laser beam is at a wavelength of 193 nm (for ArF excimer laser), Brewster's angle is about 57 degrees and each of the first and second surfaces define an apex angle of about 34 degrees.Type: GrantFiled: December 21, 1998Date of Patent: October 24, 2000Assignee: Cymer, Inc.Inventor: Alexander I. Ershov
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Patent number: 6137811Abstract: A system is disclosed for developing a conditioned electron beam of high quality for an exemplary application to a free-electron source of coherent radiation. The system comprises: a source for producing an electron beam of relatively high energy, a microwave source for generating a microwave field, and a wiggler for generating transverse to the electron beam a periodic magnetic field which cooperates with the microwave field to interact with the electron beam and develop a conditioned electron beam of high quality.Type: GrantFiled: July 29, 1993Date of Patent: October 24, 2000Assignee: The United States of America as represented by the Secretary of the NavyInventors: Phillip Sprangle, Bahman Hafizi, Glenn Joyce, Philip Serafim
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Patent number: 6097740Abstract: This disclosure relates to the production of coherent waves of electromagnetic radiation, especially of short wavelengths including X rays, in the form of pulses or continuous beams, utilizing mutually interacting beams of charged particles that include positive ions and electrons. The atoms of which the ions are formed exist in states of excitation energy by virtue of their ionization. The ions capture electrons as the two beams interact, thereby becoming capable of undergoing de-excitation and emitting characteristic electromagnetic radiation. When heavy elements and a high degree of ionization are involved, the radiation so produced can be of high frequency; often X rays. The radiation energies can be of large natural widths which make conditions favorable for the emissions to be composed into a coherent pulse or beam.Type: GrantFiled: September 29, 1998Date of Patent: August 1, 2000Inventor: Jose Chakkoru Palathingal
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Patent number: 6088379Abstract: An ultraviolet laser apparatus which generates laser light at 193 nm to 213 nm with high temporal and spatial coherence and relatively high power is disclosed. The UV laser apparatus provides a light source for an exposure device for optical lithography and an aberration measurement interferometer that measures lens wave front aberration. The laser apparatus disclosed herein comprises two lasers having laser resonators that are coincident along a portion of their respective optical paths. A nonlinear optical crystal is located along the shared optical path portion for sum frequency generation of the light of the respective lasers.Type: GrantFiled: June 9, 1998Date of Patent: July 11, 2000Assignee: Nikon CorporationInventors: Soichi Owa, Tomoko Ohtsuki
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Patent number: 6061379Abstract: Two techniques for producing plasma x-ray laser amplifiers, encompassing laser generated high density, micron-sized plasma columns, and microwave driven low density, large plasma volumes which provide the population inversions necessary for x-ray lasing to occur in the plasmas. The laser driven plasma is created by short-pulse, high power laser beams produced by chirped pulse amplification techniques, which are confined to micron-sized cylindrical channels by self-focusing effects and electron density conditioning means. The extremely high powers provide for complete stripping of medium to high Z atoms, which allows for recombination cascading to produce population inversions on the higher energy x-ray transition levels. The very short plasma creation times allow a laser produced "seed" x-ray pulse to be properly timed for injection into the plasma when population inversions reach maximum levels.Type: GrantFiled: January 19, 1999Date of Patent: May 9, 2000Inventor: Neil C. Schoen
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Patent number: 6031854Abstract: A two-step, diode-pumped solid-state laser is disclosed. A diode laser source pumps a first solid-state laser. The first solid-state laser in-turns pumps a second solid-state laser. The second solid-state laser contains all the parameters suitable for efficient deep UV generation. A direct application of the diode-pumped solid-state cascade laser is for deep UV generation for photo-refractive surgeries.Type: GrantFiled: August 24, 1999Date of Patent: February 29, 2000Inventor: Lai Ming
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Patent number: 6026099Abstract: A capillary discharge x-ray laser driven by a radial pulse forming line. Both Blumlein and transmission line configurations of the pulse forming line in single and multiple stage arrangements are presented.Type: GrantFiled: July 30, 1997Date of Patent: February 15, 2000Assignee: Tetra CorporationInventor: Chris M. Young
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Patent number: 6021141Abstract: A harmonic generator laser system which features a distributed Bragg reflector (DBR) or distributed feedback (DFB) tunable diode laser coupled to a quasi-phase matched (QPM) waveguide of optically nonlinear material. Tuning of the DBR laser may be achieved either thermally or via current injection, or both, halving the wavelength of a red laser into the visible blue spectral band. Thermal tuning may provide a coarse tuning adjustment, while injected current may provide fine tuning accessible to a user. Separately or in combination with current tuning, a modulation signal may be applied to the DBR laser for achieving an intensity modulated or a pulsed output. In another embodiment, modulation may be achieved by frequency modulation of the laser. A very compact tunable blue laser is formed. In yet another embodiment a double clad fiber amplifier is disposed between the tunable laser and the waveguide.Type: GrantFiled: February 28, 1997Date of Patent: February 1, 2000Assignee: SDL, Inc.Inventors: Derek W. Nam, David F. Welch, Robert G. Waarts, Jo S. Major
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Patent number: 6014388Abstract: A short wavelength laser includes a light source having a fundamental generating portion which emits fundamental wave and a wavelength convertor which converts the fundamental wave to its second harmonic. A light amplifier amplifies the second harmonic.Type: GrantFiled: April 30, 1997Date of Patent: January 11, 2000Assignee: Fuji Photo Film Co., Ltd.Inventor: Toshiaki Fukunaga
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Patent number: 5982801Abstract: Apparatus providing ultrasonic control of a fluid medium to provide selective motion and cavitation comprising a transducer and an associated chamber providing a controllable acoustic travelling wave therein. The chamber includes an inlet, an outlet and a tapered passage through which the liquid medium flows and/or cavitation is induced and/or controlled. Embodiments of the present invention provide the production of light by controlled sonoluminescence and the generation of electrical energy by the flow of a medium through a magnetic field.Type: GrantFiled: June 10, 1996Date of Patent: November 9, 1999Assignee: Quantum Sonic Corp., IncInventor: David Deak
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Patent number: 5940418Abstract: A solid state laser systems for generating highly monochromatic laser radiation at wavelengths of interest for advanced micro-lithography, particularly 248 nanometer and 193 nanometer wavelengths. At least one Nd:YAG laser produces a 1,064 nm laser beam consisting of narrow-linewidth pulses of infra-red laser radiation having a pulse duration of less than 30 nanoseconds, at a pulse rate preferably in excess of 500 pulses per second with pulse energy greater than 20 millijoules. This radiation is frequency doubled and frequency tripled to produce 532 nm and 355 nm pulsed laser beams. These beams are then further optically processed to generate the ultra-violet wavelength for micro-lithography at either 248 nm or 193 nm.Type: GrantFiled: November 22, 1996Date of Patent: August 17, 1999Assignee: JMAR Technology Co.Inventor: Henry Shields
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Patent number: 5916788Abstract: A genetic recombination laser apparatus includes an optical system having a semiconductor laser medium for generating a semiconductor laser light, an Nd:YAG crystal, an LBO and .beta.-BBOs for reducing the wavelength of the laser light, an acoustic optical device and a lens for converging the laser light with a reduced wavelength;. A stage for positioning the focus of the laser light converged by the lens at any arbitrary location on a specimen is provided. The energy of the laser light converged on the specimen is set at a value greater than the bonding energy of the substance composing the wall of the somatic cell. Preferably, the semiconductor laser light is converted into the fifth harmonic of an Nd:YAG laser light having a wavelength of 213 nm and a second harmonic with a wavelength of 532 nm generated in the conversion process is used as for positioning the focus of the laser light converged by the lens on the specimen.Type: GrantFiled: October 11, 1996Date of Patent: June 29, 1999Assignee: Sony CorporationInventors: Shigeo Kubota, Werner Wiechmann, Ling Yi Liu
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Patent number: 5887008Abstract: A function is introduced into a high energy electron storage ring or collider so as to form pulses of an electron beam each having a time width for causing coherence of electrons, thereby generating a high energy coherent electron beam. When a gamma-ray laser (GASER) is to be generated, a laser light projector is combined so as to cause coherent Inverse-Compton scattering of the laser light by the coherent electron beam, thereby generating a coherent gamma-ray, or GASER. This makes it possible to control elementary particle reaction and nuclear reaction (cross sections). Also, monochromaticity, directivity and luminance are improved.Type: GrantFiled: March 19, 1997Date of Patent: March 23, 1999Assignee: Japan Science and Technology CorporationInventor: Hidetsugu Ikegami
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Patent number: 5832007Abstract: An X-ray laser generating apparatus comprises a laser oscillator for generating a pulse laser beam, a pulse train converter for converting the pulse laser beam into a pulse train laser beam, an optical device for focusing the pulse train laser beam to a thin line, a target material placed at the laser beam focused position and generating high temperature plasma containing highly charged ions with irradiation of the linearly focused pulse train laser beam, a vacuum chamber for keeping a vicinity of the irradiated region of the target material under a decompressed state, and a pair of X-ray reflecting mirrors positioned on both sides of the target material and on the extended thin line, and at least one of the paired mirrors partially transmits X-ray.Type: GrantFiled: February 20, 1997Date of Patent: November 3, 1998Assignees: Toyota Jidosha Kabushiki Kaisha, Toyota School Foundation, Denso CorporationInventors: Tamio Hara, Naohiro Yamaguchi, Toshio Sata
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Patent number: 5809048Abstract: A short wavelength light source mainly comprises a semiconductor laser for pumping a laser medium, a birefringence filter for controlling or stabilizing the waveform by applying an optical feedback to the semiconductor laser to feed back only light of specific wavelength, lens systems for focusing the pumping light, and an optical resonator composed of a laser medium formed of Nd:YAG doped with 1% of Nd and a nonlinear optical element formed of KNbO.sub.3. The birefringence filter is structured as a Lyot filter, and is composed of a birefringence element made of 2 mm thick non-doped YVO.sub.4, a polarizer, and a birefringence element made of 4 mm thick non-doped YVO.sub.4.This constitution realizes a short wavelength light source achieving a single longitudinal mode oscillation while maintaining a high output, small in size, superior in efficiency, and excellent in wavelength stability.Type: GrantFiled: July 9, 1997Date of Patent: September 15, 1998Assignee: Mitsui Petrochemical Industries, Ltd.Inventors: Shiro Shichijyo, Kiyofumi Muro
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Patent number: 5805622Abstract: Disclosed is an apparatus for generating laser pulses, which has a Q-switched solid state laser and at least one nonlinear crystal, and the application of this apparatus for removing material in the biomedical field. The present invention is distinguished by the nonlinear crystal being disposed inside the resonator of the solid state laser and by a pulse prolongation unit determining the pulse form and duration of the light pulse developing in the resonator.Type: GrantFiled: April 8, 1997Date of Patent: September 8, 1998Assignee: Medizinisches Laserzentrum Lubeck GmbHInventor: Ralf Brinkmann
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Patent number: 5796762Abstract: The present invention is directed to a tunable, solid state laser utilizing room temperature, stable, color centers of LiF:F.sub.2.sup.+ ** material. Also disclosed is a method of lasing. An object of the present invention is to develop and optimize LiF:F.sub.2.sup.+ thermostabilized active media, to propose a method of pumping, and to realize a room temperature, stable and efficient operation of the color center laser. These and other objects are achieved by introducing special dopants in the crystal at the stage of crystal growing; applying special regimes of ionizing treatment of the crystal, resulting in thermostabilization of the F.sub.2.sup.+ centers in LiF crystals; and utilizing alexandrite laser radiation for color center crystal pumping with a pump radiation frequency which is appropriate for the selective excitation of the F.sub.2.sup.+ color centers.Type: GrantFiled: April 8, 1997Date of Patent: August 18, 1998Assignee: The UAB Research FoundationInventors: Sergey Mirov, Alex Dergachey
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Patent number: 5764662Abstract: An ultraviolet laser system is disclosed for generating an ultraviolet frency in the spectral region between 223 nm and 243 nm by mixing the tunable output of a Ce.sup.3+ :LiCAF laser with the 1064 nm radiation from a Nd:YAG pump laser in a BBO nonlinear crystal.Type: GrantFiled: January 27, 1997Date of Patent: June 9, 1998Assignee: The United States of America as represented by the Secretary of the NavyInventor: Joseph F. Pinto
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Patent number: 5754572Abstract: A mirrorless, distributed-feedback (DFB), ultraviolet, tunable, narrow-liidth, solid state laser for remote sensing and medical applications is disclosed. Optical pumping in the DFB laser is accomplished using a frequency quadrupled, 10 Hz., Q-switched, Nd:YAG laser operating at 266 nm. The pump beam is diffracted off a grating (2400 grooves per mm.) into two parts. The two beams are subsequently recombined at the side face of the Ce:doped crystal (8 mm.times.8 mm.times.30 mm) at an angle of about 2.theta.(about 81 degrees). The resulting spatially periodic excitation within the Ce-doped gain medium due to the interferring pump beams determines the operating wavelength of the DFB laser.Type: GrantFiled: November 15, 1996Date of Patent: May 19, 1998Assignee: The United States of America as represented by the Sectary of the Navy.Inventors: Joseph F. Pinto, Leon Esterowitz
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Patent number: 5701317Abstract: A device for maintaining a high-energy laser pulse within a recirculating optical delay line for a period time to optimize the interaction of the pulse with an electron beam pulse train comprising closely spaced electron micropulses. The delay line allows a single optical pulse to interact with many of the electron micropulses in a single electron beam macropulse in sequence and for the introduction of additional optical pulses to interact with the micropulses of additional electron beam macropulses.Type: GrantFiled: May 30, 1995Date of Patent: December 23, 1997Assignee: Duly Research Inc.Inventors: David U. L. Yu, Donald L. Bullock
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Patent number: 5659558Abstract: A first pumping beam at a wavelength of 1210 nm emitted from a first pumping source is focused by a first lens system on an optical fiber. A second pumping beam at a wavelength of 650 nm emitted from a second pumping source passes through a coupler and a second lens system and arrives at the optical fiber to be incident thereon. Tm ions with which a core portion of the optical fiber is doped sequentially experience a ground-state level absorption transition upon absorption of the first pumping beam, an excited-state level absorption transition to an upper laser level upon absorption of the second pumping beam, and a radiative transition from the upper laser level to a ground-state level, thereby emitting light at a wavelength of 460 to 500 nm. The light at a wavelength of 460 to 500 nm emitted from the Tm ions is resonated by a resonator consisting of an incident mirror and an emitting mirror and outputted as a laser beam.Type: GrantFiled: March 5, 1996Date of Patent: August 19, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Genji Tohmon, Jun Ohya, Tomoaki Uno
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Patent number: 5637962Abstract: A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28).Type: GrantFiled: June 9, 1995Date of Patent: June 10, 1997Assignee: The Regents of the University of California Office of Technology TransferInventors: Daniel S. Prono, Michael E. Jones
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Patent number: 5617443Abstract: An electron beam and a positron beam accelerated to the same energy are caused to join into a confluence in the same direction by a magnet for joining electrons and positrons, and positronium molecules or beam-shaped para-positroniums of the same phase cooled to transient Bose-Einstein condensation or the vicinity thereof are formed on the axis of confluence by a beam focusing solenoidal coil, thereby simultaneously generating gamma-ray lasers of two wavelengths which accompany annihilation caused by self-stimulated radiation, namely a forward GASER, which is a monochromatic gamma-ray laser having a photon energy of greater than several MeV and a backward GASER, which is a monochromatic gamma-ray laser having a photon energy of less than 200 keV.Type: GrantFiled: October 26, 1995Date of Patent: April 1, 1997Assignee: Research Development Corporation of JapanInventor: Hidetsugu Ikegami
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Patent number: 5617435Abstract: A semiconductor laser emits semiconductor laser light with TM-mode oscillation. The emitted semiconductor laser light is collimated by a first collimating lens, passes through a Brewster plate that is arranged so that the direction of Brewster plane's p-polarized light is in alignment with the direction of polarization of the emitted semiconductor laser light, and is coupled to an incident portion of a wavelength-conversion waveguide by means of a focusing lens. While being guided through the waveguide, the emitted semiconductor laser light is converted into second-harmonic light by means of a polarization inversion region. Semiconductor laser light emanating from an emitting portion of the waveguide reflects from an output mirror towards a diffraction grating, for modulation in wavelength. Second-harmonic light emanating from the emitting portion of the waveguide is outputted from the output mirror.Type: GrantFiled: March 16, 1995Date of Patent: April 1, 1997Assignee: Matsushita Electronics CorporationInventors: Hideo Nagai, Toru Takayama, Masahiro Kume, Akio Yoshikawa
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Patent number: 5566199Abstract: A method of producing collimated x-radiation by suitably subjecting metallic ions in the presence of lower Z ions to a pulse of laser energy from a conventional laser. An improvement on said conventional laser in order to increase the reliability of production of said collimated x-radiation. An alternative improvement on said conventional laser for similar improvement of said collimated x-radiation. An example of the application of the use of said collimated x-radiation to the art of producing micro-circuitry.Type: GrantFiled: December 22, 1994Date of Patent: October 15, 1996Inventor: John G. Kepros
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Patent number: 5491707Abstract: A high average power, high brightness solid state laser system. We first produce seed laser beam with a short pulse duration and frequency in excess of 1,000 pulses per second. A laser amplifier amplifies the seed pulse beam to produce an amplified pulse laser beam which is focused to produce pulses with brightness levels in excess of 10.sup.11 Watts/cm.sup.2. Preferred embodiments produce an amplified pulse laser beam having an average power in the range of 1 kW, an average pulse frequency of 12,000 pulses per second with pulses having brightness levels in excess of 10.sup.14 Watts/cm.sup.2 at a 20 .mu.m diameter spot which is steered rapidly to simulate a larger spot size. These beams are useful in producing X-ray sources for lithography.In one preferred embodiment, the seed beam is produced in a mode locked Nd:YAG oscillator pumped by a diode array with the frequency of the pulses being reduced by an electro-optic modulator.Type: GrantFiled: November 15, 1994Date of Patent: February 13, 1996Assignee: Jamar Technologies Co.Inventors: Harry Rieger, Henry Shields, Richard M. Foster
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Patent number: 5487078Abstract: Apparatus and method for generating prompt X-radiation from gas clusters. The present invention includes the excitation of inner-shell electrons in the atoms comprising gas clusters using intense ultraviolet laser radiation, thereby producing intense, prompt X-ray emission from the ensemble. Clusters enable atomic excitation rates to achieve the high values characteristic of condensed matter while simultaneously eliminating, through local rapid expansion to low particle density, undesirable collisional interactions that would establish equilibrium conditions in the excited material, and effectively destroy the inner-shell specificity of the excitation. By choosing the atomic species in the cluster, the laser intensity and wavelength, and the cluster size, one can determine the wavelength of X-radiation emitted from the clusters. Moreover, by selecting the energy levels involved in the excitation process, one can produce a population inversion having significant gain and suitable for lasing.Type: GrantFiled: March 14, 1994Date of Patent: January 23, 1996Assignee: Board of Trustees of the University of IllinoisInventors: Charles K. Rhodes, Keith Boyer
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Patent number: 5467362Abstract: A high current, pulsed, high repetition rate, electric discharge, extreme ultraviolet and Xray laser. The low inductance discharge bore is constructed from a plurality of discs (18). The bore segments are separated from one another by spacers constructed from a refractory electrical insulator (20). The components in contact with the gas discharge are constructed from high temperature materials with low sputtering rates and low rates of ion burial. Gas return holes (74) are provided in the bore segments discs. Xray reflecting mirrors form an optical cavity.Type: GrantFiled: August 3, 1994Date of Patent: November 14, 1995Inventor: Gordon A. Murray
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Patent number: 5452312Abstract: A short-wavelength laser light source having a semiconductor laser for emitting laser light is provided. The light source includes a power supply for driving the semiconductor laser and thereby causing the semiconductor laser to emit a fundamental wave, a polarization inversion-type light-wavelength converting device for generating from the fundamental wave a harmonic wave having a shorter wavelength than the fundamental wave; and laser light feedback means for feeding light of the fundamental wave lying in a selected wavelength region back to the semiconductor laser, thereby achieving oscillation wavelength locking. Said power supply supplies to the semiconductor laser a high-frequency power containing AC components oscillating in a cycle short enough to cause the semiconductor laser to emit the fundamental wave in the form of pulsed laser light.Type: GrantFiled: October 12, 1994Date of Patent: September 19, 1995Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kazuhisa Yamamoto, Kiminori Mizuuchi, Yasuo Kitaoka, Makoto Kato
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Patent number: 5404364Abstract: A method of producing collimated x-radiation by suitably subjecting metallic ions in the presence of lower Z ions to a pulse of laser energy from a conventional laser. An improvement on said conventional laser in order to increase the reliability of production of said collimated x-radiation. An alternative improvement on said conventional laser for similar improvement of said collimated x-radiation. An example of the application of the use of said collimated x-radiation to the art of producing micro-circuitry.Type: GrantFiled: December 29, 1993Date of Patent: April 4, 1995Inventor: John G. Kepros
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Patent number: 5394411Abstract: Optical guiding of intense laser pulses over a distance of more than one Rayleigh length in a plasma is discussed herein using a multi-pulse technique. The first pulse or pulse sequence prepares a shock-driven, axially-extended radial electron density profile which guides a second pulse or sequence of pulses. The profile is also capable of guiding x-rays. The channel will support mode structure exactly analogous to that of an optical fiber waveguide. The method provides a means for guiding of a high intensity optical laser pulse or x-rays over distances well in excess of a Rayleigh length. The distances over which guiding occurs is limited only by the length of the preformed plasma and absorption and possible backscattering of the guided EM radiation. Applications of the method allow for compact x-ray laser devices and electron particle accelerators.Type: GrantFiled: February 16, 1994Date of Patent: February 28, 1995Assignee: University of Maryland, College ParkInventors: Howard Milchberg, Charles Durfee, III
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Patent number: 5355380Abstract: A millimeter wave device. Pulses of electrons illuminate a diamond switch at rates of 1 billion to 100 billion pulses per second. The diamond switch connects a high voltage source to a millimeter wave transmitter or other load. In preferred embodiments the electron pulses are provided by a klystron or a traveling wave tube.Type: GrantFiled: December 23, 1992Date of Patent: October 11, 1994Inventors: Shiow-Hwa Lin, Lawrence H. Sverorup, Jr.
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Patent number: 5353291Abstract: The laser synchrotron source (LSS) utilizes a high peak power or high average power laser to generate within a vacuum chamber a laser beam travelling in one direction to interact with an electron beam traveling in an opposite direction in order to generate high-power x-rays. A ring resonator formed by a plurality of mirrors directs the laser beam in a closed loop to impact with the electron beam to produce x-rays. Concave mirrors in the ring resonator focus the laser beam upon the point where the laser beam interacts with the electron beam to intensify the laser energy at that point. When a radio frequency linear accelerator (rf linac) is used to produce the electron beam, x-rays having a short pulse length are generated. When a betatron is used as an electron source, x-rays having a long pulse length are generated.Type: GrantFiled: February 19, 1993Date of Patent: October 4, 1994Assignee: The United States of America as represented by the Secretary of the NavyInventors: Phillip A. Sprangle, Antonio Ting, Eric H. Esarey, Amnon Fisher, Gerard Mourou, Ravindra Sudan
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Patent number: 5317574Abstract: A method and apparatus for producing x-ray and/or extreme ultraviolet (EUV) is described. A liquid edge 2 is electrically connected to a cathode 8 via a high voltage pulse power supply 10. Liquid edge 2 is set to be parallel to cathode 8. When high voltage pulse power supply 10 is turned on, a vacuum discharge will occur in a space between liquid edge 2 and cathode 8. The plasma will be confined into a high density and high temperature thin plasma column 4 in a space near liquid edge 2 by strong magnetic field induced by the huge discharge current. A population inversion in the confined plasma column will lead to a amplified simultaneous emission of x-ray and/or EUV 6 along the axis of plasma column 4. Moreover, a large power x-ray and/or EUV laser can be built by using multi-liquid edge-shape anodes placed in a straight line and operated in a traveling-wave mode.Type: GrantFiled: December 31, 1992Date of Patent: May 31, 1994Inventor: Hui Wang
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Patent number: 5293396Abstract: A plasma generating apparatus for an extreme-ultraviolet laser that can generate high temperature plasma at high efficiency, and can form long plasma to be recombined by rapid cooling of the high temperature plasma. A shield plate including a narrow slit is disposed adjacent to a high temperature plasma source, and the high temperature plasma is discharged through the slit. Both high efficiency plasma generation and rapid expansion thereof can be simultaneously achieved by discharging high temperature plasma through the narrow slit. The rapid expansion makes it possible to form a long plasma having a large gain in an extreme-ultraviolet region. The high temperature plasma source can be readily realized by irradiating it with an exciting laser beam from behind the opposite side of the slit with regard to the high temperature plasma source directly or through a transmitting window. A closure provided in front of the slit can prevent a liquid or gas from flowing out of the slit before it is changed into plasma.Type: GrantFiled: July 14, 1992Date of Patent: March 8, 1994Assignee: Agency of Industrial Science and TechnologyInventor: Toshihisa Tomie