Abstract: A pulsed gas discharge laser operating at an output laser pulse repetition rate of greater than 4 kHz and a method of operating same is disclosed which may comprise a high voltage electrode having a longitudinal extent; a main insulator electrically insulating the high voltage electrode from a grounded gas discharge chamber; a preionizer longitudinally extending along at least a portion of the longitudinal extent of the high voltage electrode; a preionization shim integral with the electrode extending toward the preionizer. The preionizer may be formed integrally with the main insulator. The preionization shim may substantially cover the gap between the electrode and the preionizer. The apparatus and method may comprise an aerodynamic fairing attached to the high voltage electrode to present an aerodynamically smooth surface to the gas flow.

Abstract: A system and method of operating a high repetition rate gas discharge laser system. The system includes a gas discharge chamber having a hot chamber output window heated by the operation of the gas discharge laser chamber, an output laser light pulse beam path enclosure downstream of the hot chamber window and comprising an ambient temperature window, a cooling mechanism cooling the beam path enclosure intermediate the output window and the ambient window. The gas discharge chamber can include a longitudinally and axially compliant ground rod, including a first end connected to a first chamber wall, a second end connected to a second chamber wall, the second chamber wall opposite the first chamber wall and a first portion formed into a helical spring, the ground rod providing mechanical support for a preionizer tube.

Abstract: A cross-flow fan impeller for circulating gas in a transversely excited, pulsed, gas discharge laser is disclosed and may comprise a plurality of hubs, the hubs spaced apart along the impeller's rotation axis and establishing at least two impeller segments wherein a first segment has an output flow within 80-120% of a second segment and the first and second segment having differing blade pass frequencies. In some embodiments of this aspect, the first segment may have n number of blades the second segment m number of blades, and m?n. In one embodiment, the impeller may be configured with n=29 and m=23 and in another embodiment, the impeller may be configured with n=23 and m=19. The impeller may be configured wherein n and m are prime numbers.

Abstract: A movable electrode assembly for use in a laser system, includes a first electrode having a first discharge surface, a second electrode having a second discharge surface. The second electrode being arranged opposite from the first electrode. The second discharge surface being spaced apart from the first discharge surface by a discharge gap. A discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A method of adjusting a discharge gap is also disclosed.

Abstract: A movable electrode assembly for use in laser system includes a first electrode, a second electrode arranged opposite from the first electrode, the second electrode being spaced apart from the first electrode by a discharge gap and a discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A movable electrode assembly for integration into a housing of a laser system includes a first electrode having a discharge surface, a second electrode having a discharge surface, such that the discharge surface of the first electrode and the discharge surface of the second electrode face each other in a spaced apart setting that defines a desired discharge gap, and a mechanism for moveably adjusting the spaced apart setting toward the desired discharge gap. A method of adjusting a discharge gap is also disclosed.

Abstract: A movable electrode assembly for use in a laser system, includes a first electrode having a first discharge surface, a second electrode having a second discharge surface. The second electrode being arranged opposite from the first electrode. The second discharge surface being spaced apart from the first discharge surface by a discharge gap. A discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A method of adjusting a discharge gap is also disclosed.

Abstract: A system and method of operating a high repetition rate gas discharge laser system. The system includes a gas discharge chamber having a hot chamber output window heated by the operation of the gas discharge laser chamber, an output laser light pulse beam path enclosure downstream of the hot chamber window and comprising an ambient temperature window, a cooling mechanism cooling the beam path enclosure intermediate the output window and the ambient window. The gas discharge chamber can include a longitudinally and axially compliant ground rod, including a first end connected to a first chamber wall, a second end connected to a second chamber wall, the second chamber wall opposite the first chamber wall and a first portion formed into a helical spring, the ground rod providing mechanical support for a preionizer tube.

Abstract: A movable electrode assembly for use in laser system includes a first electrode, a second electrode arranged opposite from the first electrode, the second electrode being spaced apart from the first electrode by a discharge gap and a discharge gap adjuster interfaced with at least one of the second electrode or the first electrode, the discharge gap adjuster configured to adjust the discharge gap. A movable electrode assembly for integration into a housing of a laser system includes a first electrode having a discharge surface, a second electrode having a discharge surface, such that the discharge surface of the first electrode and the discharge surface of the second electrode face each other in a spaced apart setting that defines a desired discharge gap, and a mechanism for moveably adjusting the spaced apart setting toward the desired discharge gap. A method of adjusting a discharge gap is also disclosed.

Abstract: Disclosed herein are systems and methods for extending one or both of the discharge electrodes in a transverse discharge gas laser chamber in which one or both the electrodes are subject to a dimensional change due to erosion. Electrode extension can be performed to increase the chamber life, increase laser performance over the life of the chamber, or both. Operationally, the inter-electrode spacing may be adjusted to maintain a specific target gap distance between the electrodes or to optimize a specific parameter of the laser output beam such as bandwidth, pulse-to-pulse energy stability, beam size, etc.

Abstract: A pulsed gas discharge laser operating at an output laser pulse repetition rate of greater than 4 kHz and a method of operating same is disclosed which may comprise a high voltage electrode having a longitudinal extent; a main insulator electrically insulating the high voltage electrode from a grounded gas discharge chamber; a preionizer longitudinally extending along at least a portion of the longitudinal extent of the high voltage electrode; a preionization shim integral with the electrode extending toward the preionizer. The preionizer may be formed integrally with the main insulator. The preionization shim may substantially cover the gap between the electrode and the preionizer. The apparatus and method may comprise an aerodynamic fairing attached to the high voltage electrode to present an aerodynamically smooth surface to the gas flow.

Abstract: A pulsed gas discharge laser operating at an output laser pulse repetition rate of greater than 4 kHz and a method of operating same is disclosed which may comprise a high voltage electrode having a longitudinal extent; a main insulator electrically insulating the high voltage electrode from a grounded gas discharge chamber; a preionizer longitudinally extending along at least a portion of the longitudinal extent of the high voltage electrode; a preionization shim integral with the electrode extending toward the preionizer. The preionizer may be formed integrally with the main insulator. The preionization shim may substantially cover the gap between the electrode and the preionizer.

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: A corona-discharge type, preionizer assembly for a gas discharge laser is disclosed. The assembly may include an electrode and a hollow, dielectric tube that defines a tube bore. In one aspect, the electrode may include a first elongated 0o conductive member having a first end disposed in the bore of the tube. In addition, the electrode may include a second elongated conductive member having a first end disposed in the bore and spaced from the first end of the first conductive member. For the assembly, the first and second conductive members may be held at a same voltage potential.

Abstract: A method and apparatus if disclosed which may comprise a high power high repetition rate gas discharge laser UV light source which may comprise: a gas discharge chamber comprising an interior wall comprising a vertical wall and an adjacent bottom wall; a gas circulation fan creating a gas flow path adjacent the interior vertical wall and the adjacent bottom wall; an in-chamber dust trap positioned a region of low gas flow, which may be along an interior wall and may comprise at least one meshed screen, e.g., a plurality of meshed screens, which may comprise at least two different gauge meshed screens. The dust trap may extend along the bottom interior wall of the chamber and/or a vertical portion of the interior wall. The dust trap may comprise a first meshed screen having a first gauge; a second meshed screen having a second gauge smaller than the first gauge; and the second meshed screen intermediate the first meshed screen and the interior wall.

Abstract: A cross-flow fan impeller for circulating gas in a transversely excited, pulsed, gas discharge laser is disclosed and may comprise a plurality of hubs, the hubs spaced apart along the impeller's rotation axis and establishing at least two impeller segments wherein a first segment has an output flow within 80-120% of a second segment and the first and second segment having differing blade pass frequencies. In some embodiments of this aspect, the first segment may have n number of blades the second segment m number of blades, and m?n. In one embodiment, the impeller may be configured with n=29 and m=23 and in another embodiment, the impeller may be configured with n=23 and m=19. The impeller may be configured wherein n and m are prime numbers.

Abstract: A window assembly for a pressurized laser discharge chamber is disclosed and may include a housing that is formed with a recess. The assembly may also include an optic having a first side that is exposed to chamber pressure and an opposed second side, and a compliant member that may be positioned in the recess to space the second side of the optic from the housing under normal chamber operating pressures. For the assembly, the compliant member may be compressible to allow the optic to mechanically abut the assembly housing during a chamber overpressure.

Abstract: A gas discharge laser includes a laser chamber containing a halogen laser gas, two electrode elements defining a cathode and an anode, each having a discharge receiving region defining two longitudinal edges and having a region width defining a width of an electric discharge between the electrode elements in the laser gas. The anode comprising a first anode portion comprising a first anode material defining a first anode material erosion rate, located entirely within the discharge receiving region, a pair of second anode portions comprising a second anode material defining a second anode material erosion rate, respectively located on each side of the first anode portion and at least partially within the discharge receiving region; an electrode center base portion integral with the first anode portion; and wherein each of the respective pair of second anode portions is mechanically bonded to the center base portion.

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 a F2 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 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: 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