Including A Specified Gas Additive Patents (Class 372/60)
-
Patent number: 6496527Abstract: Xenon gas is added from a small-sized Xe gas cylinder (15) to the excimer laser gas inside a chamber (10) supplied from an Ar/Ne gas cylinder (13) and an Ar/Ne/F2 gas cylinder (14), the xenon gas proportion is detected by an Xe gas sensor (16), and the supply of the xenon gas supplied to the chamber (10) from the Xe gas cylinder (15) is controlled by a gas controller (18).Type: GrantFiled: September 26, 2000Date of Patent: December 17, 2002Assignee: Komatsu, Ltd.Inventors: Katsutomo Terashima, Osamu Wakabayashi, Akira Sumitani
-
Patent number: 6490308Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber preferably less than 0.2 mbar per injection. A number of successive injections is performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters. The amount per injection and/or the interval between injections may be varied based on the measured value of the driving voltage and/or a calculated amount of the constituent gas in the discharge chamber.Type: GrantFiled: April 1, 2002Date of Patent: December 3, 2002Assignee: Lambda Physik AGInventors: Hans-Stephan Albrecht, Klaus Wolfgang Vogler, Thomas Schroeder
-
Patent number: 6490307Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a constituent gas of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The constituent gas of the laser gas mixture is provided at an initial partial pressure and the constituent gas is subject to depletion within the laser discharge chamber. A parameter such as time, pulse count, driving voltage for maintaining a constant laser beam output energy, pulse shape, pulse duration, pulse stability, beam profile, bandwidth of the laser beam, temporal or spatial coherence, discharge width, or a combination thereof, which varies with a known correspondence to the partial pressure of the constituent gas is monitored. Injections of the constituent gas are performed each to increase the partial pressure by a selected amount in the discharge chamber.Type: GrantFiled: November 23, 1999Date of Patent: December 3, 2002Assignee: Lambda Physik AGInventors: Bruno Becker de Mos, Uwe Stamm, Klaus Vogler
-
Patent number: 6487229Abstract: A system is provided for delivering a laser beam of wavelength less than 200 nm from a laser, such as an F2 laser or ArF laser, through a sealed enclosure sealably connected to the laser, and preferably to another housing, leading ultimately to a workpiece. The enclosure is preferably evacuated and back-filled with an inert gas to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter or alternatively, an inert gas flow is established and maintained within the enclosure during operation of the laser. The inert gas preferably has high purity, e.g., more than 99.5% and preferably more than 99.999%, wherein the inert is preferably nitrogen or a noble gas. The enclosure is preferably sealed by a window transparent to the sub-200 nm radiation for preventing contaminants generated in the enclosure from entering the housing and contaminating surfaces therein. The enclosure is preferably made of steel and/or copper, and the window is preferably made of CaF2.Type: GrantFiled: September 26, 2001Date of Patent: November 26, 2002Assignee: Lambda Physik AGInventors: Sergei V. Govorkov, Klaus Wolfgang Vogler, Frank Voss, Rainer Pätzel
-
Patent number: 6480517Abstract: An electrode arrangement for a gas laser is provided. The electrode arrangement includes an elongated high voltage electrode, an elongated ground electrode disposed adjacent to the high voltage electrode, a discharge gap between the two electrodes an insulator element, a high voltage conductor having a first end connected to the high voltage electrode and extending through the insulator element, and a shadow plate interposed between the discharge gap and the insulator element. The electrode arrangement may be employed in a variety of gas lasers, including excimer lasers.Type: GrantFiled: February 22, 2000Date of Patent: November 12, 2002Assignee: TuiLaser AGInventors: Claus Strowitzki, Hans Kodeda
-
Patent number: 6426966Abstract: A molecular fluorine (F2) laser is provided wherein the gas mixture comprises molecular fluorine for generating a spectral emission including two or three closely spaced lines around 157 nm. An etalon provides line selection such that the output beam only includes one of these lines. The etalon may also serve to outcouple the beam and/or narrow the selected line. Alternatively, a prism provides the line selection and the etalon narrows the selected line. The etalon may be a resonator reflector which also selects a line, while another element outcouples the beam. The etalon plates comprise a material that is substantially transparent at 157 nm, such as CaF2, MgF2, LiF2, BaF2, LiF, SrF2, quartz and fluorine doped quartz. The etalon plates are separated by spacers comprising a material having a low thermal expansion constant, such as invar, zerodur®, ultra low expansion glass, and quartz.Type: GrantFiled: September 8, 2000Date of Patent: July 30, 2002Assignee: Lambda Physik AGInventors: Dirk Basting, Sergei V. Govorkov, Uwe Stamm
-
Patent number: 6404795Abstract: A laser is provided having a gain medium including a laser gas and a photoabsorbing species. The photoabsorbing species has at least one photoabsorption line within an output emission spectrum of the laser. When the laser is an ArF-excimer laser, the photoabsorbing species is preferably either atomic carbon or molecular oxygen, which are formed after carbon- or oxygen-containing molecules introduced into the gain medium with the laser gas interact within the gain medium. An absolute wavelength of a narrowed emission of the laser can be calibrated when a narrowed output emission of the laser is tuned through at least one photoabsorption line of the photo-absorbing species. Preferably, a processor communicates with a detector and a wavelength selection unit, as well as a power supply when output beam energy is held constant, to automatically perform the calibration.Type: GrantFiled: July 27, 2001Date of Patent: June 11, 2002Assignee: Lambda Physik AGInventors: Uwe Leinhos, Jürgen Kleinschmidt, Wolfgang Zschocke, Uwe Stamm
-
Patent number: 6381257Abstract: A tunable injection seeded very narrow band F2 lithography laser. The laser combines modular design features of prior art long life reliable lithography lasers with special techniques to produce a seed beam operated in a first gain medium which beam is used to stimulate narrow band lasing in a second gain medium to produce a very narrow band laser beam useful for integrated circuit lithography. In a preferred embodiment, two tunable etalon output couplers are used to narrow band an F2 laser and the output of the seed laser is amplified in an F2 amplifier.Type: GrantFiled: December 28, 1999Date of Patent: April 30, 2002Assignee: Cymer, Inc.Inventors: Alexander I. Ershov, Eckehard D. Onkels, Palash P. Das, William N. Partlo, Thomas Hofmann
-
Patent number: 6327290Abstract: A system is provided for delivering a laser beam of wavelength less than 200 nm from a laser, such as an F2 laser or ArF laser, through a sealed enclosure sealably connected to the laser, and preferably to another housing, leading ultimately to a workpiece. The enclosure is preferably evacuated and back-filled with an inert gas to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter or alternatively, an inert gas flow is established and maintained within the enclosure during operation of the laser. The inert gas preferably has high purity, e.g., more than 99.5% and preferably more than 99.999%, wherein the inert is preferably nitrogen or a noble gas. The enclosure is preferably sealed by a window transparent to the sub-200 nm radiation for preventing contaminants generated in the enclosure from entering the housing and contaminating surfaces therein. The enclosure is preferably made of steel and/or copper, and the window is preferably made of CaF2.Type: GrantFiled: June 14, 2000Date of Patent: December 4, 2001Assignee: Lambda Physik AGInventors: Sergei V. Govorkov, Klaus Wolfgang Vogler, Frank Voss, Rainer Pätzel
-
Patent number: 6317448Abstract: A wavelength system for measuring the bandwidth of a narrowband laser utilizing prior art equipment normally provided for calibrating wavelength measurement equipment. The prior art includes a wavemeter for measuring incremental changes in wavelength and an atomic wavelength reference for calibrating the wavemeter. The atomic wavelength reference includes a vapor cell for providing a vapor having at least one absorption line near a desired operating wavelength. The system includes a wavelength tuning device with a tuning range sufficient to tune the laser to operate at the wavelength of the absorption line in order to calibrate the wavemeter. Measurements of the bandwidth of the absorption spectrum obtained by scanning the laser output wavelength over the absorption line are used to estimate the bandwidth of the output beam. This estimate in a preferred embodiment is used to confirm the accuracy of the normal bandwith measurements. In a preferred system the laser is a KrF laser and the vapor is iron vapor.Type: GrantFiled: September 23, 1999Date of Patent: November 13, 2001Assignee: Cymer, Inc.Inventors: Palash P. Das, Jesse D. Buck
-
Patent number: 6263007Abstract: A laser assembly, particularly one employing a gas lasing medium, has at least one lasing gas supply reservoir that is separate from the housing enclosure for the laser's optical cavity. A flexible or semi-flexible conduit supplies lasing gas from the reservoir to the optical cavity, so as to allow the laser per se and the gas reservoir to be manufactured separately and then connected by the tubing, thus simplifying the design and manufacturing process. The laser is preferably operated as a pulsed gas discharge laser that produces a continuous laser output. One or both of the laser's cavity mirrors may be coated with fine parallel lines which constrain the laser output to be linearly polarized. The lasing medium may have a stepwise or tapered structure, which provides for selection of the most desirable TEM00 mode. In addition, the lasing medium cavity may be cooled by a multiple cooling jacket structure to facilitate placement of the coolant inlet and outlet ports.Type: GrantFiled: November 25, 1998Date of Patent: July 17, 2001Assignee: T & S Team IncorporatedInventor: Fuqian Tang
-
Patent number: 6243405Abstract: A technique of stabalizing during operation a gas mixture with a gas composition initially provided within a discharge chamber of an excimer or molecular fluorine gas discharge laser includes monitoring a temporal pulse shape of the laser beam and adjusting and/or determining the status of the gas mixture based on the monitored temporal pulse shape. The monitored temporal pulse shape is preferably compared with a reference temporal pulse shape. The difference or deviation between the monitored temporal pulse shape and a reference temporal pulse shape is calculated. The amount of and intervals between gas replenishment actions are determined based on the calculated deviation. The energy of the beam is also monitored and the driving voltage and gas actions are adjusted to stabilize the energy, energy stability and/or energy dose.Type: GrantFiled: January 18, 2000Date of Patent: June 5, 2001Assignee: Lambda Physik AGInventors: Stefan Borneis, Klaus Brunwinkel, Uwe Stamm, Frank Voss
-
Patent number: 6188710Abstract: The present invention provides a very narrow band pulse excimer laser capable of producing pulses at a rate in the range of about 500 to 2000 Hz with enhanced energy dose control and reproducibility. Very small quantities of a stablizing additive consisting of oxygen or a heavy noble gas (xenon or radon for KrF lasers, or krypton, xenon or radon for ArF lasers), are added to the gas mixture. Tests performed show substantial improvements in energy stability with the addition of about 30 ppm of xenon to a KrF laser. Tests show improved performance for the ArF lasers with the addition of about 6-10 ppm of Xe or 40 ppm of Kr. In a preferred embodiment very narrow bandwidth is achieved on a KrF laser by reducing fluorine partial pressure to less than 0.10 percent and by increasing the reflectance of the output coupler to greater than 25 percent. In a preferred embodiment, prior art fused silica beam expansion prisms used in the prior art line-narrowing module were replaced with calcium fluoride prisms.Type: GrantFiled: July 27, 1999Date of Patent: February 13, 2001Assignee: Cymer, Inc.Inventors: Herve A. Besaucele, Toshihiko Ishihara, Thomas Hofmann
-
Patent number: 6175583Abstract: There is disclosed a metal vapour laser comprising a discharge tube having a buffer gas therein and operating at high temperature, the buffer gas including a laser output power enhancing substance in an amount sufficient to substantially increase the power output of the laser. There is also disclosed a process for operating a metal vapour laser of the invention.Type: GrantFiled: December 1, 1998Date of Patent: January 16, 2001Assignee: Macquarie Research LTDInventors: James Austin Piper, Robert John Carman, Michael John Withford, Daniel John Brown
-
Patent number: 6157662Abstract: An F.sub.2 -laser has a discharge chamber containing a laser gas mixture including fluorine as a laser active component and neon as a buffer gas. The gas mixture is surrounded by a resonator and supplied with a pulsed discharge by a pair of electrodes connected to a power supply circuit. The concentration of neon within the gas mixture is preferably higher than any other constituent gas, and is more preferably the only gas accompanying the laser active molecular fluorine. In addition, the gas mixture is preferably maintained at an elevated temperature such as near, yet below, a temperature at which outgassing occurs within the discharge chamber.Type: GrantFiled: May 24, 1999Date of Patent: December 5, 2000Assignee: Lambda Physik GmbHInventors: Michael Scaggs, Frank Voss
-
Patent number: 6018537Abstract: The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod.Type: GrantFiled: March 19, 1999Date of Patent: January 25, 2000Assignee: Cymer, Inc.Inventors: Thomas Hofmann, Jean-Marc Hueber, Palash P. Das, Toshihiko Ishihara, Thomas P. Duffey, John T. Melchior, Herve A. Besaucele, Richard G. Morton, Richard M. Ness, Peter C. Newman, William N. Partlo, Daniel A. Rothweil, Richard L. Sandstrom
-
Patent number: 6014398Abstract: The present invention provides a very narrow band pulse excimer laser capable of producing pulses at a rate in the range of about 500 to 2000 Hz with enhanced energy dose control and reproducibility. Very small quantities of a stablizing additive consisting of oxygen or a heavy noble gas (xenon or radon for KrF lasers, or krypton, xenon or radon for ArF lasers), are added to the gas mixture. Tests performed show substantial improvements in energy stability with the addition of about 30 ppm of xenon to a KrF laser. Tests show improved performance for the ArF lasers with the addition of about 6-10 ppm of Xe or 40 ppm of Kr. In a preferred embodiment very narrow bandwidth is achieved on a KrF laser by reducing fluorine partial pressure to less than 0.10 percent and by increasing the reflectance of the output coupler to greater than 25 percent. In a preferred embodiment, prior art fused silica beam expansion prisms used in the prior art line-narrowing module were replaced with calcium fluoride prisms.Type: GrantFiled: May 20, 1998Date of Patent: January 11, 2000Assignee: Cymer, Inc.Inventors: Thomas Hofmann, Toshihiko Ishihara, Palash P. Das, Alexander I. Ershov
-
Patent number: 5982800Abstract: A very narrow band pulse excimer laser capable of producing pulses at a rate in the range of about 500 to 2000 Hz with enhanced energy dose control and reproducibility. A prior art burst mode "slug effect" occuring at one gas circulation time after the beginning of a burst of pulses is eliminated by the addition of a minute quantity of oxygen. In a preferred embodiment very narrow bandwidth is achieved by reducing fluorine partial pressure to less than 0.10 percent and by increasing the reflectance of the output coupler to greater than 25 percent. In a preferred embodiment, prior art fused silica beam expansion prisms used in the prior art line narrowing module were replaced with calcium fluoride prisms.Type: GrantFiled: October 10, 1997Date of Patent: November 9, 1999Assignee: Cymer, Inc.Inventors: Toshihiko Ishihara, Thomas Hofmann, Palash P. Das, Alexander I. Ershov
-
Patent number: 5978394Abstract: A wavelength system for measuring and controlling the wavelength of a narrowband laser. The system includes a wavemeter for measuring incremental changes in wavelength and an atomic wavelength reference for calibrating the wavemeter. The atomic wavelength reference includes a vapor cell for providing a vapor having at least one absorption line near a desired operating wavelength. The system includes a wavelength tuning device with a tuning range sufficient to tune the laser to operate at the wavelength of the absorption line in order to calibrate the wavemeter.In a preferred embodiment, the laser is an ArF laser, and the vapor is platinum and the absorption line is either 193,224.3 pm or 193,436.9. Improvements over prior art devices include an improved etalon having a support flange to provide a low stress three-point hanging support for the etalon without use of elastomers.Type: GrantFiled: October 2, 1998Date of Patent: November 2, 1999Assignee: Cymer, Inc.Inventors: Peter C. Newman, Richard L. Sandstrom
-
Patent number: 5682400Abstract: Disclosed is a gas laser utilizing high frequency discharge 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 and provides for pre-ionization of the gaseous medium before using high frequency discharge excitation. The gas is supplied into a receiver, and has downstream therefrom a supersonic nozzle for acceleration of the active gaseous flow to high subsonic or supersonic speeds in order to provide intensive dynamic cooling of the active gas medium. The gas is excited using high frequency discharge excitation in the critical area of the supersonic nozzle or downstream therefrom. The high frequency discharge and excitation can also occur within the optical resonator region which is located within the supersonic area of the nozzle. The present invention provides compact, efficient and super-powerful continuous, quasi-continuous and pulse laser systems with wavelengths from 0.3 mkm to 10.Type: GrantFiled: September 27, 1995Date of Patent: October 28, 1997Inventor: Alexander V. Krasnov
-
Patent number: 5658488Abstract: Provided is method and apparatus for regenerating basic hydrogen peroxide (BHP) solution. Such solution is run through filters which are alternated for continuous filtration thereof, while the non-used filter is being cleaned. The filtered BHP solution is then reacted with H.sub.2 O.sub.2 and KO.sub.2 or KOH in a cooled reactor and again filtered and fed to a cooled storage tank as replenished BHP solution. The replenished BHP solution can then be fed to a singlet oxygen generator (SOG) for reaction with Cl.sub.2 to emit singlet delta oxygen (to fuel a COIL laser system) and depleted BHP solution, which is then recycled for filtration and regeneration as before. Thus the process of the invention provides for continuous regeneration of BHP solution for extended use in a COIL. That is, extended COIL run times are required by a COIL for welding and/or cutting operations. At the same time the process of the invention minimizes the amount of BHP required to run the COIL since the BHP is regenerated and recycled.Type: GrantFiled: April 11, 1995Date of Patent: August 19, 1997Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Thomas J. Lonergan, John C. Horrocks
-
Patent number: 5629952Abstract: A package for a high power semiconductor laser comprising a hermetically sealed container filled with a dry gaseous medium containing oxygen. The presence of oxygen in the laser atmosphere is counter to standard practice in the art which teaches the use of an atmosphere of a dry inert gas. The package also includes a getter for organic impurities, e.g., a getter composed of a porous silica or a zeolite. The hydrogen content of the materials used to form the package are reduced by baking at an elevated temperature for an extended period of time, e.g., at 150.degree. C. for 200 hours.Type: GrantFiled: June 7, 1995Date of Patent: May 13, 1997Assignee: Corning IncorporatedInventors: Roger F. Bartholomew, Paul A. Jakobson, Douglas W. Hall, Julia A. Sharps
-
Patent number: 5513198Abstract: A package for a high power semiconductor laser comprising a hermetically sealed container filled with a dry gaseous medium containing oxygen. The presence of oxygen in the laser atmosphere is counter to standard practice in the art which teaches the use of an atmosphere of a dry inert gas. The package also includes a getter for organic impurities, e.g., a getter composed of a porous silica or a zeolite. The hydrogen content of the materials used to form the package are reduced by baking at an elevated temperature for an extended period of time, e.g., at 150.degree. C. for 200 hours.Type: GrantFiled: December 17, 1993Date of Patent: April 30, 1996Assignee: Corning IncorporatedInventor: Paul A. Jakobson
-
Patent number: 5452317Abstract: A metal vapor laser apparatus is provided with a buffer gas and a laser medium are enclosed in a tube and the gas is utilized as an excitation or ionization medium in the tube. The metal vapor laser apparatus comprises molecules consisting of a plurality of elements and mixed by at least 0.1% in the gas enclosed in the tube and a gas having a molecular weight lighter than that of neon mixed by at least 0.1% in the gas enclosed in the tube.Type: GrantFiled: September 22, 1994Date of Patent: September 19, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoichiro Tabata, Kazuhiko Hara, Akihiko Iwata, Shigeo Ueguri, Hiroshi Masuda, Yoshibumi Minowa
-
Patent number: 5450433Abstract: A laser arrangement includes an outer envelope and an inner alumina tube between which insulating material is located. The insulating material has a plurality of apertures therein in its transverse end faces, the aperture being arranged at each end on two circle of similar radii. Hydrogen reservoirs are located within the apertures. During operation of the laser arrangement, the reservoirs become heated causing hydrogen to be evolved and diffused through to the laser active medium, improving the efficiency of the laser operation. When laser action ceases, the arrangement cools and hydrogen returns to the reservoirs. Efficiency enhancing gases other than hydrogen may be used in the arrangement.Type: GrantFiled: December 9, 1993Date of Patent: September 12, 1995Assignee: English Electric Valve Company LimitedInventors: Ewan S. Livingstone, Graeme L. Clark
-
Patent number: 5440578Abstract: An excimer gas laser using a fluorine/krypton/neon gas mixture is provided with separate fluorine/krypton/neon and krypton/neon gas sources for use in replenishing the gas mixture. A bleed-down mechanism is also provided for draining a portion of the gas mixture from the excimer laser. A control mechanism controls operation of the separate fluorine/krypton/neon and krypton/neon sources and the bleed-down mechanism to selectively vary the gas mixture within the excimer laser to maintain an overall optimal laser efficiency. Preferably, the control system monitors operational parameters of the excimer laser including gain, wavelength, bandwidth and pulse rate, to determine whether the gas mixture within the excimer laser may have changed from an optimal mixture. The control system controls operation of the separate fluorine/krypton/neon and krypton/neon sources to compensate for changes in the operation parameters of the laser to thereby maintain high overall laser efficiency.Type: GrantFiled: July 16, 1993Date of Patent: August 8, 1995Assignee: Cymer Laser TechnologiesInventor: Richard L. Sandstrom
-
Patent number: 5425045Abstract: A laser optical apparatus permits the use of a laser beam having a spectrum characteristic which substantially overlaps with an absorption band of oxygen, with a simple construction. Oxygen in a lens barrel of an optical system or a sealed space between lens barrels is absorbed by a deoxidation agent. Accordingly, even if a laser beam by an excimer laser using argon fluoride having a spectrum characteristic which substantially overlaps with the absorption of oxygen is passed through the optical system, the loss of laser energy by the absorption of oxygen, the generation of noxious gas and the swing due to the change of transmission are prevented.Type: GrantFiled: July 22, 1994Date of Patent: June 13, 1995Assignee: Nikon CorporationInventor: Masato Hamatani
-
Patent number: 5418801Abstract: To a laser medium comprising vapor of metal atoms A is added vapor of metal atoms B such that the difference .DELTA.E(B) between the energy value E.sub.1 (B) at the upper laser level and the energy value at the lower laser level E.sub.2 (B) as the metastable state after laser transition or fluorescent transition is substantially equal to the energy level E.sub.2 (A) of the metal atoms A at the lower laser level. Secondary collision of the metal atoms A in the E.sub.2 (A) state and the metal atoms B in the E.sub.2 (B) state with one another causes energy transition, whereby the metal atoms A do a work of exciting the metal atoms B to a resonant excitation level to lose its own energy and undergo transition to a ground level E.sub.0 (A). Consequently, the excitation lifetime at the lower laser level in the laser transition is reduced to extend the inverse population time and also the laser output pulse width so as to increase the laser conversion efficiency.Type: GrantFiled: October 8, 1993Date of Patent: May 23, 1995Assignee: Chuo Electric Works Co., Ltd.Inventor: Hiroshi Saitoh
-
Patent number: 5396514Abstract: An excimer laser including a gas reservoir in which gas discharge is effected with the participation of halogen gas, comprises a collecting receptacle which communicates both with the gas reservoir and a halogen gas supply through conduits provided with shutoff valves. This apparatus is suitable for carrying out a method of refilling the gas reservoir of the excimer laser with halogen gas even if the pressure of the halogen gas supply is low and its volume restricted.Type: GrantFiled: March 1, 1993Date of Patent: March 7, 1995Assignee: Lamba Physik Gesellschaft zur Herstelling von Lasern mbHInventor: Frank Voss
-
Patent number: 5377217Abstract: A rare gas-halide excimer laser uses a buffer gas consisting of from 5 to 50% by volume helium the balance being neon.Type: GrantFiled: April 2, 1993Date of Patent: December 27, 1994Assignee: The BOC Group plcInventor: Jacek T. Gabzdyl
-
Patent number: 5373524Abstract: Mixing power laser apparatus, comprising a generator of a flow of excited nitrogen (1), and structure (6; 19) to introduce a flow of CO.sub.2 into the flow of excited nitrogen. The generator (1) is of the cold corona electric discharge type operating at a pressure greater than 0.3.times.10.sup.5 Pa, and is coupled to a waveguide (2) with mirrors (3, 4) opposed along a principal direction of the waveguide. For use particularly in cutting material.Type: GrantFiled: May 11, 1993Date of Patent: December 13, 1994Assignee: L'Air Liquide, Societe Anonyme Pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Bruno Marie, Daniel Guerin, Christian Larquet
-
Patent number: 5353296Abstract: An laser system is disclosed for materials processing. The system includes an RF excited, conduction cooled, sealed gas laser. The lasing species in the gas mixture is an isotope of carbon dioxide and in the preferred embodiment is defined by the .sup.13 CO.sub.2 isotope. The use of the .sup.13 CO.sub.2 isotope functions to shorten the rise and fall times of the laser pulses. By this arrangement, the laser may be operated at higher repetition rates with a full depth of power modulation.Type: GrantFiled: July 12, 1993Date of Patent: October 4, 1994Assignee: Coherent, Inc.Inventor: Dale E. Koop
-
Patent number: 5339327Abstract: Metal vapor laser apparatus includes a laser tube and a reactor chamber in which is contained metal which may be copper in the form of granules. Neon is introduced via one input port of the chamber and a halogen or halogen donor gas through another input port. A coil surrounds the reactor chamber and provides heating to its interior. The gas passes over the metal to form metal halide at its surface and is vaporized by the heating effects. The buffer gas and metal halide are then transmitted via a conduit into the laser tube where dissociation of the metal halide and subsequent excitation of metal vapor is carried out to produce laser radiation.Type: GrantFiled: July 12, 1993Date of Patent: August 16, 1994Assignee: EEV LimitedInventors: Ewan S. Livingstone, Graeme L. Clark
-
Patent number: 5307364Abstract: The present invention relates to discovery that oxygen may be used to stabilize the efficiency and performance of an excimer laser. Therefore, oxygen is not a contaminant to be minimized but rather a necessary part of an excimer lasing composition.Type: GrantFiled: May 24, 1993Date of Patent: April 26, 1994Assignee: Spectra Gases, Inc.Inventor: Brian A. Turner
-
Patent number: 5301203Abstract: The scalable and stable, cw photolytically excited atomic iodine laser operates at 1.315 nm. An initial power level of 55 watts/liter was obtained via the cw photolysis of an alkyl-iodide gas like C.sub.3 F.sub.7 I. The greatly enhanced laser performance was achieved using a microwave excited, electrodeless Hg plasma lamp excited with a d.c., low ripple cw microwave radiation. Both high flow, air cooling and liquid dimethyl polysiloxane cooling of these high pressure Hg lamps provided long lifetime operation with the latter promoting, stable laser operation. Transverse flow of the above gas for the removal of the quenching by-product I.sub.2 is incorporated into the laser. To insure good laser amplitude stability, both the high power magnetrons and the lamps are liquid cooled. The scalable, prolonged and stable operation of this laser system is possible via use of a closer cycle, condensative/evaporative fuel system coupled to a high flow, internal blower for heavy gases.Type: GrantFiled: September 23, 1992Date of Patent: April 5, 1994Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: LaVerne A. Schlie, Robert D. Rathge
-
Patent number: 5300859Abstract: A source of IR-radiation, having an enclosure defining between its walls a sealed-off, electrode-less chamber, the walls having at least one portion transparent to IR-radiation, and the chamber containing a gas mixture of at least one, molecular, IR-active gas, of at least one buffer gas and of at least one noble gas. A method for producing a source of IR-radiation is also described and claimed.Type: GrantFiled: March 19, 1991Date of Patent: April 5, 1994Assignee: Yissum Research Development Company of the Hebrew University of JerusalemInventors: Shaul Yatsiv, Amnon Gabay
-
Patent number: 5283800Abstract: A metal vapor laser apparatus has a gas supply device. The device supplies at least two kinds of gases to a container of the laser apparatus controlled individually. One of the gases is selected from the group of the molecular gas such as hydrogen gas, the other is selected from the group of rare gas such as neon gas. By adjusting the mixture ratio of these gases, the laser beam output is obtained efficiently. The molecular gas should be supplied when a metal lump, such as copper, arranged in the container is melting.Type: GrantFiled: March 26, 1992Date of Patent: February 1, 1994Assignee: Kabushiki KaishaToshibaInventors: Setsuo Suzuki, Yasushi Iseki, Ikuo Watanabe, Kazuo Hayashi, Etsuo Noda, Tomoko Ogawa, Hironobu Kimura, Nobutada Aoki
-
Patent number: 5199041Abstract: A method of modulating an oxygen-iodine laser comprises applying an external magnetic field having an intensity of up to 800 A.cm.sup.-1 to the active zone of the laser and, at the same time, changing the magnetic field intensity to change the output power of the laser.Type: GrantFiled: July 12, 1991Date of Patent: March 30, 1993Assignee: Ceskoslovenka Akademie VedInventors: Josef Schmiedberger, Jarmila Kodymova, Jiri Kovar, Otomar Spalek, Pavel Trenda
-
Patent number: 5185771Abstract: The Charge Coupled Device ("CCD"), which is an integrated circuit array sensor in "chip" form, of a pushbroom spectrographic imager is operated to achieve fast dumping of unwanted rows of charges. The chip is provided with antiblooming structure in the image area and the first row of the storage area. The rows of charges are divided into groups of several rows. The groups of interest (i.e. the active groups) and those that are not wanted (i.e. the discard groups) are so designated. The rows in each group are summed in the antiblooming structure of the storage area. The active summed rows are sequentially transferred by the chip's transport register to an output amplifier, wherein the individual charges are read out and digitized to yield signal values for collection. The discard summed rows are cleared without digitization.Type: GrantFiled: July 13, 1990Date of Patent: February 9, 1993Assignee: Itres Research LimitedInventors: Clifford D. Anger, Stephen K. Babey
-
Patent number: 5166947Abstract: A method and laser apparatus are disclosed which provide for a cross-flow of gas near one end of a laser discharge tube. The cross-flow of gas causes a concentration gradient which affects diffusion of contaminants in the discharge tube towards the cross-flow of the gas, which contaminants are then withdrawn from the discharge tube.Type: GrantFiled: September 29, 1986Date of Patent: November 24, 1992Assignee: The United States of America as represented by the United States Department of EnergyInventor: David B. Duncan
-
Patent number: 5029178Abstract: An improved nitrogen laser includes two oppositely disposed discharge electrodes contained within a resonant chamber that is supplied with a mixture of nitrogen gas and a substantially small amount of electronegative gas. The mixture used within the chamber makes it possible to operate the nitrogen laser at a high voltage output and a higher frequency rate.Type: GrantFiled: January 2, 1990Date of Patent: July 2, 1991Assignee: Horiba, Ltd.Inventor: Yoshihiro Tarui
-
Patent number: 5023883Abstract: This invention discloses a system for generating a continuous wave (CW) chemically pumped laser in the visible and ultraviolet wavelength regions of the spectrum. This invention employs controlled condensation to produce a non-equilibrium species of metal atoms such as the sodium trimer (Na.sub.3). Continuous, coherent radiation output is achieved by producing from a convergent divergent nozzle a high speed jet of metal vapor carrier by a non-reacting gas such as nitrogen (N.sub.2). By control of the expansion rate and temperature of the metal vapor and carrier gas mixture, a metal trimer species is produced. Also from a convergent divergent nozzle a second high speed jet is produced that carries halogen atoms (such as fluorine, chlorine, bromine, or iodine) in an inert gas such as helium. The high speed jets of reactants flow in parallel. The two high speed jets of gases, alternating in halogen and metal vapor flow, output into a laser cavity. Upon mixing these gases, a chemical reaction results.Type: GrantFiled: September 26, 1989Date of Patent: June 11, 1991Inventors: Theodore A. Jacobs, George Emanuel
-
Patent number: 4991180Abstract: A metallic vapor laser apparatus includes a cylindrical discharge tube (31) having an internal space (2), a heat-insulating material (6) encompassing the periphery of the discharge tube (31), and two electrodes (3a) and (3b) having a cylindrical portion coaxial with the discharge tube (31) and disposed at both ends of the discharge tube (31). The internal space (2) are filled with a gas containing the vapor of copper as a laser medium for effecting laser oscillation by the excitation of the filler gas and the discharge.Type: GrantFiled: May 18, 1990Date of Patent: February 5, 1991Assignee: Hitachi, Ltd.Inventors: Motoo Yamaguchi, Hiroyuki Sugawara, Akira Wada, Toshiharu Shirakura, Tuneyoshi Oohashi, Toshimichi Kichikawa
-
Patent number: 4945546Abstract: A chemical laser comprising means for producing metal trimers, means for dissociating halogen molecules, a reaction chamber, and means for delivering the metal trimer and halogen atoms into the reaction chamber to form electronically excited metal dimer molecules in sufficient concentration to create a population inversion and laser amplification.Type: GrantFiled: January 4, 1989Date of Patent: July 31, 1990Assignee: Georgia Tech Research CorporationInventors: James L. Gole, James R. Woodward, Stephen H. Cobb
-
Patent number: 4899362Abstract: In a laser arrangement, solid or liquid material, at least part of which comprises a laser amplifying medium, is atomized in a gas prior to being applied to a discharge region. In one embodiment of the invention, the gas is combustible and is ignited to produce a flame which provides heating of the material. The invention is particularly applicable to metal vapour lasers.In another embodiment of the invention, the material is atomized in an inert gas and a discharge within a laser discharge tube is used to provide excitation.Type: GrantFiled: December 5, 1988Date of Patent: February 6, 1990Assignee: EEV LimitedInventors: Arthur Maitland, Ewan S. Livingstone
-
Patent number: 4888786Abstract: A CO.sub.2 gas laser is equipped with a gas mixture control arrangement which introduces into the interior of the laser, of the constituent component of water, only hydrogen, in such amounts based on the instantaneous humidity of the gas mixture that the dew point of water vapor resulting from the combination of the thus introduced hydrogen with incidental oxygen present in the laser interior as an incident to the operation of the laser is maintained within a predetermined range.Type: GrantFiled: May 9, 1988Date of Patent: December 19, 1989Assignee: United Technologies CorporationInventors: Jack W. Davis, Clyde O. Brown
-
Patent number: 4873693Abstract: A laser comprises an interaction region formed by a wall surface of a capillary discharge tube which has been roughened along a continuous length thereof. This roughened surface suppresses and substantially eliminates diffraction rings in lasers.Type: GrantFiled: November 30, 1988Date of Patent: October 10, 1989Assignee: Melles Griot San Marcos CompanyInventor: Benjamin H. Cook, Jr.
-
Patent number: 4868840Abstract: A metal vapor laser device wherein the pressure of carrier gas within a metal vapor laser tube can be normally maintained constant and a stabilized laser beam can be generated. The metal vapor laser device comprises a metal vapor laser tube, and a carrier gas supplier for supplementing carrier gas into the metal vapor laser tube. The carrier gas supplier includes an outer tube substantially impermeable to the carrier gas, and an inner tube having a permeability to the carrier gas which varies according to temperature and partitioning the inside of the outer tube into a reservoir section and a tank section. The inner tube is disposed in the tank section of the outer tube in such a manner as to form a duplex tube. The carrier gas supplier further includes a heater provided on outer peripheries of regions of the outer tube including the reservoir section and the tank section.Type: GrantFiled: September 29, 1988Date of Patent: September 19, 1989Assignee: Ushio Deki Kabushiki KaishaInventors: Kyoichi Deki, Shinji Sugioka, Masaki Yoshioka, Hiroshige Hata
-
Patent number: 4841537Abstract: A medium for a gas laser excited by ionizing particles containing helium, neon, argon or krypton with a total concentration in excess of 10.sup.19 cm.sup.-3 with argon or krypton concentration ranging from 3.multidot.10.sup.16 cm.sup.-3 to a value amounting to 15% of the total concentration. The medium additionally comprises at least one more component selected from the group comprising, xenon, hydrogen, hydrogen isotope, or a mixture of these components in various combinations, the concentration of each component or the mixture thereof being selected from a range from 10.sup.15 cm.sup.-3 to a value equal to 20% of the concentration of argon or krypton.Type: GrantFiled: September 27, 1988Date of Patent: June 20, 1989Inventors: Andrei J. Alexandrov, Viktor A. Dolgikh, Oleg M. Kerimov, Alexei J. Samarin, Igor G. Rudoi, Arkady M. Soroka
-
Patent number: 4817096Abstract: A transverse electrically excited gas laser comprises a mixture of rare gases and a fluorine donor at selected partial pressures so as to permit UV and/or visible rare gas-halide laser oscillation at two or more wavelengths simultaneously.Type: GrantFiled: August 29, 1988Date of Patent: March 28, 1989Assignee: United Technologies CorporationInventors: William L. Nighan, Roland A. Sauerbrey, Frank K. Tittel