Abstract: An injection locking type or MOPA type of laser device capable of always providing stable output energy and wavelength is provided. For this purpose, the laser device includes an oscillator for exciting laser gas by oscillator discharge and oscillating seed laser light with band-narrowed wavelength, an amplifier for amplifying the seed laser light by amplification discharge to emit amplified laser light, a delay circuit for setting at least one of a delay time from light emission of the seed laser light to light emission of the amplified laser light, and a delay time from start of the oscillator discharge to start of the aforementioned amplification discharge, and a delay time compensation circuit for performing compensation of the delay circuit so that the delay time becomes an optimal delay time.

Abstract: A gas laser oscillator includes a supply-side valve for regulating a laser gas supply to a gas chamber, an exhaust-side valve for regulating a laser gas exhaust from the gas chamber, a gas pressure measuring device for measuring a pressure in the gas chamber, and a control device functioning as a laser gas replacement measuring device. The control device makes a first measurement and a second measurement of the pressure in the gas chamber by a gas pressure measuring device at a predetermined time interval during the vacuuming or purging of the gas chamber, and determines the laser gas replacement amount per unit time during the laser oscillating operation, based on the results of the first and second measurements.

Abstract: A pressure-recovery device for a supersonic, continuous wave gas laser is capable of recovering the pressure of the supersonic fluid in an efficient manner and in a relatively light and compact assembly. The supersonic diffuser has a substantially rectangular inlet and top and bottom walls that extend from the inlet in the direction of the flow of gas. The top and bottom walls are separated by a height (l1) at the inlet and are connected by two side walls. The side walls are separated by a width (h) at the inlet, wherein the ratio of height to width ranges at the inlet from about 0.001 to about 1. A compression region is formed by the top wall, bottom wall and side walls, wherein said top and bottom walls either are or are not symmetric about a central longitudinal axis of the compression region.

Abstract: A startup method capable of easily and inexpensively activating a laser oscillator by limiting an output current of a high-frequency power supply, without using a particular element or a complicated system, even when the laser oscillator is activated in a low-temperature environment, and a gas laser unit having such a function. According to the normal pressure control, the laser gas is gradually increased from pressure p1 to pressure p2. However, in the invention, when DC current reaches a certain threshold at time t3, a feedback control of the laser gas is executed after time t3 such that the DC current does not exceed the threshold. In this case, the laser gas pressure is controlled so as to increase to pressure p2? which is smaller than pressure p2.

Abstract: An RF excited gas laser including an offset V-shaped laser cavity. The laser includes a first and second ceramic body portions with the laser cavity at least partially defined by the ceramic body portions. At least one internal gas reservoir is also at least partially defined by the first and second body portions, with the internal gas reservoir being in gas communication with laser cavity by way of at least one gas communication slot. The RF laser further includes at least two electrode slots formed in the exterior of the ceramic body portions and an electrode at least partially received in the electrode slots.

Abstract: A continuous wave laser based on the electronic I*(2P½)?I(2P 3/2) transition of atomic iodine at 1.315 microns from the NCl(a1?)+I(2P 3/2) energy transfer reaction using a transverse flow device having gas flow from an upstream subsonic combustor section through a converging-diverging supersonic slit nozzle to a downstream supersonic section and an intersecting optical resonator. Laser operation is achieved through the transformation of the gas phase chemical reagents, D2 (deuterium), F2 (fluorine), NF3 (nitrogen trifluoride), DCl (deuterium chloride) HI (hydrogen iodide) in the subsonic section and HN3 (hydrogen azide) in the supersonic section.

Abstract: Systems and methods for efficiently operating a gas discharge excimer laser are disclosed. The excimer laser may include a chamber containing laser gases, first and second electrodes within the chamber, and a plurality of reflective elements defining an optical resonant cavity. The method may include setting the laser gases to a first pressure; after setting the gases to the first pressure, applying a first voltage to the electrodes, thereby propagating a laser beam in the optical resonant cavity; measuring energy of the beam; adjusting the first voltage until the energy of the beam is substantially equal to a target pulse energy; operating the laser for an amount of time; after the amount of time, measuring energy of the beam; and changing the pressure of the gases to a second pressure different from the first pressure.

Abstract: A laser processing system includes a laser processing means, a gas mixing unit, and a controller. The controller controls and adjusts the composition of the process gas for laser processing. The controller includes a data storage for technology tables by means of which the composition of the process gas is controlled and adjusted.

Abstract: A gas discharge laser apparatus is disclosed. In an embodiment, the gas discharge laser apparatus includes a gas laser provided with a discharge chamber, and a gas storage chamber in controllable fluid communication with the discharge chamber via a valve member, the gas storage chamber configured to have a pressure lower therein than in the discharge chamber such that, when the valve member is controlled to bring the gas storage chamber into fluid communication with the discharge chamber, gas is removed from the discharge chamber.

Abstract: A charging voltage Vosc applied to a main capacitor C0 disposed in an oscillating high-voltage pulse generator 12 of an oscillating laser 100 is subject to constant control such that a pulse energy Posc of the oscillating laser 100 becomes a lower limit energy Es0 or more of an amplification saturation region. And, a charging voltage Vamp applied to a main capacitor C0 disposed in an amplifying high-voltage pulse generator 32 of an amplifying laser 300 is controlled, and pulse energy Pamp of the amplifying laser 300 is determined as target energy Patgt. Thus, the pulse energy of a two-stage laser is controlled to stabilize the pulse energy.

Abstract: To provide an excimer laser device and method in which the frequency of full gas exchange within the laser chamber is reduced, and more preferably full gas exchange is made unnecessary. The gas supply device and gas exhaust device are controlled so that the laser gas in the laser chamber is partially exchanged in a gas exchange quantity that maintains the quantity of impurities in the laser chamber at or below a fixed level. Also, the gas exchange quantity is obtained using the total quantity of output light energy reduction A, the total gas pressure in the laser chamber P, and output light energy reduction quantity per unit time k, for the case where partial gas exchange is repeated infinitely in the laser chamber.

Abstract: A chamber for a gas discharge laser is disclosed and may include a chamber housing having a wall, the wall having an inside surface surrounding a chamber volume and an outside surface, the wall also being formed with an orifice. For the chamber, at least one electrical conductor may extend through the orifice to pass an electric current into the chamber volume. A member may be disposed between the conductor and the wall for preventing gas flow through the orifice to allow a chamber pressure to be maintained in the volume. The chamber may further comprise a pressurized compartment disposed adjacent to the orifice for maintaining a pressure on at least a portion of the outside surface of the wall to reduce bowing of the wall near the orifice due to chamber pressure.

Abstract: A line narrowing method and module for a narrow band DUV high power high repetition rate gas discharge laser producing output laser light pulse beam pulses in bursts of pulses, the module having a nominal optical path are disclosed which may comprise: a dispersive center wavelength selection optic moveably mounted within an optical path of the line narrowing module, selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic; a first tuning mechanism operative in part to select the angle of incidence of the laser light pulse beam containing the respective pulse upon the dispersive center wavelength selection optic, by selecting an angle of transmission of the laser light pulse beam containing the pulse toward the dispersive center wavelength selection optic; a second tuning mechanism operative in part to select the angle of incidence of the laser light pu

Abstract: In an laser oscillator (100), a blower (10, 20, 120) for circulating a laser medium between an electric discharge tube (102) and a circulating passage (104) includes: a casing (12) having a suction port (12a) and an exhaust port (12b); and a blade (18) pivotally supported in the casing (12) so that the blade (18) can face the suction port (12a) and the exhaust port (12b). The blade (18) is formed into a shape in which a diameter of the blade (18) is different at a position on a cross section perpendicular to a rotary central line (O), and a gap (Go) between a portion, in which a diameter of the blade (18) is relatively large, and the casing is larger than a gap (Gi) between a portion, in which a diameter of the blade (18) is relatively small, and the casing. Due to the foregoing, a highly reliable blower used for a laser oscillator, the reduction of the blower efficiency of which is suppressed to be as small as possible, can be provided.

Abstract: A gas laser apparatus including a laser oscillating section including a blower forcibly circulating a medium gas in a medium circuit, and a blower monitoring section monitoring a maintenance state of the blower. The blower includes a lubricant storage chamber storing a lubricant, and a lubricant monitoring chamber connected to the lubricant storage chamber to ensure fluidic communication therebetween at a position lower than an oil level of a lubricant having a predetermined appropriate volume and stored in the lubricant storage chamber.

Abstract: Flow laminators are attached to gas introducing parts installed in a laser generator preventing impurities from attaching to surfaces of a translucent mirror and a condensing lens. The flow laminators prevent airflow from producing a turbulent flow and air on the surface of the mirror and the lens are cleaned up, therewith reducing attachment of impurities further.

Abstract: A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the use of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Abstract: An slab CO2 laser includes spaced-apart elongated slab electrodes. A lasing gas fills a discharge gap between the electrodes. An RF power supply is connected across the electrodes and sustains an electrical discharge in the lasing gas in the discharge gap. Either one or two ceramic inserts occupy a portion of width of the electrodes and in contact with the electrodes. A discharge gap is formed between the portions of the width of the electrodes not occupied by the insert or inserts. Provision of the ceramic insert or inserts increases the resistance-capacitance (RC) time constant of the electrode impedance by increasing the capacitive component of the time constant. This hinders the formation of arcs in the discharge, which, in turn enables the inventive laser to operate with higher excitation power or higher lasing-gas pressure than would be possible without the dielectric insert. The ceramic insert also decreases the difference in impedance of the electrodes with and without a discharge.

Abstract: An excimer laser comprises a gas chamber, electrodes for creating rare gas/halide molecules that disassociate and produce optical emission, and reflective surfaces that form an optical resonant cavity. The excimer laser further comprises flow control surfaces that define gas flow paths and that control the flow of gas within the chamber. Preferably such flow control surfaces direct the gases away from the laser optics. More preferably, the flow control surfaces shield the path of the laser beam, at least in the proximity of the laser optics, from contaminants in the gases. Less contaminants yields less contamination of the laser optics. As a result, the laser device becomes more reliable and useful over longer periods of time. In addition, the laser gases are preferably exposed only to compatible materials that react with the laser gases to produce stable reaction products having a low vapor pressure, so as to reduce contamination of the gases and the optics.

Abstract: A gas laser oscillator includes a supply-side valve for regulating a laser gas supply to a gas chamber, an exhaust-side valve for regulating a laser gas exhaust from the gas chamber, a gas pressure measuring device for measuring a pressure in the gas chamber, and a control device functioning as a laser gas replacement measuring device. The control device makes a first measurement and a second measurement of the pressure in the gas chamber by a gas pressure measuring device at a predetermined time interval during the vacuuming or purging of the gas chamber, and determines the laser gas replacement amount per unit time during the laser oscillating operation, based on the results of the first and second measurements.

Abstract: A method and apparatus are disclosed for controlling the output of a two chamber gas discharge laser comprising an oscillator gas discharge laser and an amplifier gas discharge laser that may comprise establishing a multidimensional variable state space comprising a coordinate system having at least two coordinates, each coordinate comprising a selected variable representing an operating parameter of the oscillator or the amplifier; tracking a multidimensional operating point in the multidimensional variable state space according to the variation of the selected variables in either or both of the oscillator or the amplifier to determine the position of the multidimensional operating point in the multidimensional state space; determining from the position of the multidimensional operating point in the multidimensional operating space a region from a plurality of defined regions in the multidimensional operating space in which the multidimensional operating point is located and identifying the region.

Abstract: Feedback timing control equipment and process for an injection seeded modular gas discharge laser. A preferred embodiment is a system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts or greater. The feedback timing control is programmed to permit in some circumstances discharges timed so that no significant laser energy is output from the system. Use of this technique permits burst mode operation in which the first discharge of a burst is a no-output discharge so that timing parameters for each of the two chambers can be monitored before the first laser output pulse of the burst. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber.

Abstract: An electric discharge, narrow band gas laser with improvements in wavelength stability. Improvements result from reduced laser beam directional fluctuations or fast correction of those fluctuations. Applicant has discovered, using an extremely sensitive knife edge optical technique, that gas discharge laser windows in a trapezoidal configuration were causing slight wavelength perturbations when laser gas density varied during laser operation. The optical technique involves using test laser beam directed through the discharge region of the gas discharge laser, blocking a portion of the beam with a knife edge and measuring the non-blocked portion of the beam to monitor beam deflection. With this technique, Applicant can measure beams deflection with an accuracy of about 0.3 microradians and with a time response of about 1 microsecond.

Abstract: A laser oscillating apparatus includes a discharger for exciting a laser medium, a blower for blowing a laser gas and a laser gas path for connecting the discharger and the blower, and a laser oscillating apparatus characterized in that the blower includes a shaft portion provided with a blade wheel portion at a front end thereof, a driving portion for rotating the shaft portion, and a partition wall portion for separating the blade wheel portion and the driving portion, and a surface of the partition wall portion is provided with a metal layer dispersing precipitated polytetrafluoroethylene (PTFE).

Abstract: An excimer laser with a laser chamber containing a circulating laser gas containing fluorine and long-life, annealed, copper alloy electrodes. Electrode lifetime is increased by annealing them after the electrodes are machined. This annealing relieves the surface stress caused by the machining operation and reduces the exposed metallic grain boundary length per unit area on the surface of the electrodes, which provides substantial reduction in erosion caused by fluorine chemical attack. Annealing after machining also reduces the stress throughout the bulk of the electrode material. In preferred embodiments the anode is a copper-aluminum alloy and the cathode is a copper-zinc alloy.

Abstract: Pulse parameters of a gas discharge laser system can be optimized and controlled for precision applications such as microlithography. Important laser pulse parameters typically vary in the beginning of a pulse burst, and the directionality of the output beam typically varies throughout the burst. In order to improve the performance of the laser system, the variation at the beginning of a pulse burst can be eliminated by extending the pulse pattern and shuttering the output during periods of significant parameter variation. A fast shutter such as an acousto-optical modulator can be used to prevent output during the burst transition processes. Elements such as acousto-optical cells also can be used in combination with a fast position sensor to steer the direction of the output beam, in order to adjust for variations in the direction of the beam between pulses in a burst.

Abstract: An integrated circuit lithography technique called spectral engineering by Applicants, for bandwidth control of an electric discharge laser. In a preferred process, a computer model is used to model lithographic parameters to determine a desired laser spectrum needed to produce a desired lithographic result. A fast responding tuning mechanism is then used to adjust center wavelength of laser pulses in a burst of pulses to achieve an integrated spectrum for the burst of pulses approximating the desired laser spectrum. The laser beam bandwidth is controlled to produce an effective beam spectrum having at least two spectral peaks in order to produce improved pattern resolution in photo resist film. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection control system having a time response of less than about 2.0 millisecond.

Abstract: A gas laser oscillator achieving a substantial increase in laser output is provided. This gas laser oscillator includes a permeable screen plate at a position of a laser gas passage and can increase the laser output substantially by suppressing and uniformizing laser gas pulsation in a discharge tube.

Abstract: An apparatus and method for producing laser output light pulses in bursts of pulses, at a selected pulse repetition rate, forming a laser output light beam, separated by an off time is disclosed, which may comprise a laser output light pulse beam parameter adjustment system, which may comprise a laser output light pulse beam parameter error detector providing a beam parameter error signal representative of the difference between the beam parameter and a selected target value for the beam parameter; a beam parameter adjustment mechanism; a beam parameter adjustment mechanism controller providing a beam parameter adjustment signal to the beam parameter adjustment mechanism based upon the value of the beam parameter error signal; a slow transient compensator providing a slow transient inversion signal modifying the beam parameter adjustment signal based upon the value of the beam parameter error signal.

Abstract: An injection locking type or MOPA type of laser device capable of always providing stable output energy and wavelength is provided. For this purpose, the laser device includes an oscillator for exciting laser gas by oscillator discharge and oscillating seed laser light with band-narrowed wavelength, an amplifier for amplifying the seed laser light by amplification discharge to emit amplified laser light, a delay circuit for setting at least one of a delay time from light emission of the seed laser light to light emission of the amplified laser light, and a delay time from start of the oscillator discharge to start of the aforementioned amplification discharge, and a delay time compensation circuit for performing compensation of the delay circuit so that the delay time becomes an optimal delay time.

Abstract: A laser system (52A) is illustrated having a laser cavity (54) that generates a laser beam (78). An outcoupling resonator box (62) has a reflective mirror (70) therein. A return resonator box (64) has a reflective mirror (72) therein. A first solid window assembly (66) is disposed between the outcoupling resonator box (62) and the laser cavity (54). A second solid window assembly (68) is disposed between the return resonator box (64) and the laser cavity (54) so that the beam (78) is directed through the solid window assemblies (66), (68) during operation of the laser system, thereby isolating the usually caustic environment of laser cavity (54) from that of mirrors (70), (72) that are housed in said resonator boxes (62), (64), without the use of isolation valves and optical tunnels as in traditional arrangements.

Abstract: There is to provide a laser apparatus that emits a laser beam by exciting gas enclosed in a chamber, including a gas characteristic detecting mechanism for detecting a characteristic of the gas in the chamber, and a calculation mechanism for calculating an oscillation wavelength and/or a wavelength spectral bandwidth of the laser beam based on a detected result by the gas characteristic detecting mechanism.

Abstract: A line-narrowing module for a laser includes a prism beam expander and a grating preferably attached to a heat sink. A pressure-controlled enclosure filled with an inert gas seals the grating and/or other elements of the line-narrowing module. The pressure in the enclosure is adjusted for tuning the wavelength. Preferably, the pressure is controlled by controlling the flow of an inert gas through the enclosure. A pump may be used, or an overpressure flow may be used. Alternatively, a prism of the beam expander or an etalon may be rotatable for tuning the wavelength.

Abstract: A laser and method for operating a laser and disclosed. The laser may include a first discharge electrode and a second discharge electrode positioned at a distance from the first electrode. A laserable gas may be provided together with a circulation system to flow the gas into a space between the electrodes. A voltage source may be connected to the electrodes for creating a discharge in the space; and a flow guide having a guide surface in contact with the gas may be provided that is guide selectively moveable relative to the first electrode to guide a flow of gas into the space. In one implementation, the flow guide directs flow toward an extremity of the first electrode and is adjustable to direct flow toward the extremity as the first electrode wears.

Abstract: An oscillator-amplifier gas discharge laser system and method is disclosed which may comprise a first laser unit which may comprise a first discharge region which may contain an excimer or molecular fluorine lasing gas medium; a first pair of electrodes defining the first discharge region containing the lasing gas medium, a line narrowing unit for narrowing a spectral bandwidth of output laser light pulse beam pulses produced in said first discharge region; a second laser unit which may comprise a second discharge chamber which may contain an excimer or molecular fluorine lasing gas medium; a second pair of electrodes defining the second discharge region containing the lasing gas medium; a pulse power system providing electrical pulses to the first pair of electrodes and to the second pair of electrodes producing gas discharges in the lasing gas medium between the respective first and second pair of electrodes, and laser parameter control mechanism modifying a selected parameter of a selected laser output lig

Abstract: Disclosed is a method of performing assay to a fluorite sample, which includes a first step for dissolving a fluorite sample, containing Ca and F, by use of a solvent, a second step for removing Ca and F from an obtained solution, and a third step for assaying, through ICP-MS, the solution having Ca and F removed therefrom. Also disclosed is a method of producing a fluorite crystal and an exposure apparatus using such fluorite crystal, and a device manufacturing method using such exposure apparatus. The assaying method of the present invention ensures assay and evaluation of a fluorite sample, of sensitivity several times higher than conventional methods.

Abstract: In a gas laser device, a laser gas sealingly stored in a chamber is excited using a discharging electrode that is electrically discharged. Laser light produced by the electrical discharging is totally reflected by a total reflection mirror. An output window partially reflects the laser light and outputs a portion of the laser light reflected between the total reflection mirror and the output window. A blower circulates the laser gas within the chamber so that the laser gas passing an electrical discharging region of the discharging electrode is circulated in the chamber and is returned to the electrical discharging region of the discharging electrode. The blower is operated according to the state of electrical discharging from the discharging electrode.

Abstract: The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems.

Abstract: An injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in an ArF excimer laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan providing sufficient gas flow to permit operation at pulse rates of 4000 Hz or greater by clearing debris from the discharge region in less time than the approximately 0.25 milliseconds between pulses.

Abstract: The present invention provides systems and methods for filtering particles and assisting gas flow management within laser systems. In one embodiment, a laser apparatus (100) includes an elongate laser chamber defining a chamber cavity (130) and an electrode structure (140) disposed therein. The electrode structure includes an anode (148) spaced apart from a cathode (146). The laser includes an elongate baffle (174) disposed in the laser chamber. The baffle is adapted to arrest a plurality of particles generated within the chamber. In this manner, the baffle operates as a passive filtration system to help filter particles generated within the chamber during laser operation, and may further provide gas flow management capabilities.

Abstract: An injection locking type or MOPA type of gas laser device which requires only a small installation area and allows easy maintenance. For this purpose, the laser device includes a seed laser unit (11) for exciting a laser gas inside a laser chamber (12) and oscillating seed laser light (21) and an amplifier (111) for exciting a laser gas inside an amplifying chamber (112) and amplifying pulse energy of the seed laser light (21), and allows the laser chamber (12) and the amplifying chamber (112) to be evacuated to the same side with respect to an optical axis of the seed laser light (21).

Abstract: A method and apparatus is provided for stabilizing output beam parameters of a gas discharge laser by maintaining a molecular fluorine component of the laser gas mixture at a predetermined partial pressure using a gas supply unit and a processor. The molecular fluorine is provided at an initial partial pressure and is subject to depletion within the laser discharge chamber. Injections of gas including molecular fluorine are performed each to increase the partial pressure of molecular fluorine by a selected amount in the laser chamber preferably less than 0.2 mbar per injection, or 7% of an amount of F2 already within the laser chamber. A number of successive injections may be performed at selected intervals to maintain the constituent gas substantially at the initial partial pressure for maintaining stable output beam parameters.

Abstract: An automatic F2 laser gas control, for a modular high repetition rate ultraviolet gas discharge laser. The laser gas control includes techniques, monitors, and processor for monitoring the F2 consumption rates through the operating life of the laser system. These consumption rates are used by a processor programmed with an algorithm to determine F2 injections needed to maintain laser beam quality within a delivery range. Preferred embodiments include F2 controls for a two-chamber MOPA laser system.

Abstract: An injection locking type or MOPA type of laser device capable of always providing stable output energy and wavelength is provided. For this purpose, the laser device includes an oscillator for exciting laser gas by oscillator discharge and oscillating seed laser light with band-narrowed wavelength, an amplifier for amplifying the seed laser light by amplification discharge to emit amplified laser light, a delay circuit for setting at least one of a delay time from light emission of the seed laser light to light emission of the amplified laser light, and a delay time from start of the oscillator discharge to start of the aforementioned amplification discharge, and a delay time compensation circuit for performing compensation of the delay circuit so that the delay time becomes an optimal delay time.

Abstract: The present invention provides a gas discharge laser having at least one long-life elongated electrode for producing at least 12 billion high voltage electric discharges in a fluorine containing laser gas. In a preferred embodiment at least one of the electrodes is comprised of a first material having a relatively low anode erosion rate and a second anode material having a relatively higher anode erosion rate. The first anode material is positioned at a desired anode discharge region of the electrode. The second anode material is located adjacent to the first anode material along at least two long sides of the first material. During operation of the laser erosion occurs on both materials but the higher erosion rate of the second material assures that any tendency of the discharge to spread onto the second material will quickly erode away the second material enough to stop the spread of the discharge.

Abstract: A laser having a lasing chamber and a semiconductor pumping device with trivalent titanium ions dissolved in a liquid host within the lasing chamber. Since the host is a liquid, it can be removed from the optical cavity when it becomes heated avoiding the inevitable optical distortion and birefringence common to glass and crystal hosts.

Abstract: In laser-plasma generation, a fluid of target material is jet out to form a jet tube target 21 having a diameter ? and a wall thickness ? with a shell and a hollow space within the shell by using a core-column. A plurality of pulse-like laser beams 30 are directed to the jet tube target radially and equiangularly-spaced directions and are simultaneously focused and irradiated onto the jet tube target to generate the plasma.

Abstract: The present invention relates to a long pulse gas laser apparatus for lithography further improved in the laser oscillation efficiency and stability increased by addition of xenon gas. A gas laser apparatus for lithography has a pair of discharge electrodes 2 provided in a laser chamber 1 and emits laser beam having a laser pulse width (Tis) of not less than 40 ns by exciting a laser gas sealed in the laser chamber 1 by electric discharge between the pair of discharge electrodes 2, the laser gas containing xenon in an amount not less than 2 ppm and not more than 100 ppm in partial pressure ratio. The laser gas has been heated at least when the laser beam is emitted.

Abstract: Plate springs as coupling members can absorb deformation of an oscillator case due to heat and do not transmit the deformation to two optical bases constituting an optical resonator, and it is thereby possible to maintain an appropriate positional relation between the optical cases. A harmful deformation force is produced due to imperfect alignment deformation of bellows each of which is connected between the oscillator case and each optical base. The plate springs can also suppress the force acting on the two optical bases, and it is thereby possible to keep a laser optical axis of a laser beam to be a fixed position.

Abstract: Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode.