Abstract: The invention relates to a two-stage laser system well fit for semiconductor aligners, which is reduced in terms of spatial coherence while taking advantage of the high stability, high output efficiency and fine line width of the MOPO mode. The two-stage laser system for aligners comprises an oscillation-stage laser (50) and an amplification-stage laser (60). Oscillation laser light having divergence is used as the oscillation-stage laser (50), and the amplification-stage laser (60) comprises a Fabry-Perot etalon resonator made up of an input side mirror (1) and an output side mirror (2). The resonator is configured as a stable resonator.

Abstract: A method/apparatus may comprise a laser light source which may comprise a solid state seed laser system producing a seed laser output having a nominal center wavelength at a pulse repetition rate; a first and a second gas discharge laser amplifier gain medium each operating at a pulse repetition rate less than that of the seed laser system; a beam divider providing each of the respective first and second amplifier gain mediums with seed laser output pulses; a frequency converter modifying the nominal center wavelength of the output of the seed laser to essentially the nominal center wavelength of the amplifier gain medium; a beam combiner combining the outputs of the respective amplifier gain mediums to provide a light source output having the pulse repetition rate of the seed laser; a coherence buster operating on either or both of the output of the seed laser or amplifier gain mediums.

Abstract: A slab type laser apparatus has a slab type gas laser medium part formed in a region defined by a pair of electrode flat plates oppositely disposed in parallel with each other in a space to be filled with a gas laser medium which is excited by high-frequency electric power. The apparatus includes an oscillator part including a pair of resonator mirrors oppositely disposed with a part of the gas laser medium part in between, and for amplifying a laser beam to have predetermined light intensity to emit the laser beam, and the amplifier part including a plurality of return mirrors oppositely disposed with a part of the gas laser medium part in between. The incident laser beam goes and returns plural times between the return mirrors, and the laser beam is amplified to have predetermined power.

Abstract: A pulsed CO2 laser is Q-switched by an intracavity acousto-optic (AO) Q-switch including an AO material transparent at a fundamental wavelength of the laser. In one example the AO material is germanium.

Abstract: An operating method of an excimer laser system includes following steps. First, a halogen gas with an injection volume is injected into a chamber until a pressure of the chamber is a total pressure. The halogen gas in the chamber has a halogen pressure. Thereafter, a driving voltage is provided between two electrodes in the chamber so as to start the excimer laser system. The halogen pressure and a full width half maximum of a laser light generated by the excimer laser system have negative relation, and the halogen pressure and the driving voltage have positive relation.

Abstract: An apparatus and method which may comprise a seed laser defining an optical cavity producing an output. An amplifier may amplify the seed laser output. A bandwidth error signal generator may provide a bandwidth error signal from measured bandwidth and a target. A bandwidth selection element, which may comprise an adjustable sized aperture external to the cavity of the seed laser may selectively alter the bandwidth of the seed laser output. A bandwidth control system may control the bandwidth control element and also selectively adjust a differential firing time between the seed laser and amplifier or another bandwidth selection actuator to cooperated (coarsely or finely) with the bandwidth selection element to control bandwidth of the laser system.

Abstract: An RF-excited waveguide laser module comprises a first electrode having a first elongate surface defining in part a waveguide laser channel extending along an optical axis, the first elongate surface having a substantially linear cross-section normal to the optical axis. A second electrode has a second elongate surface defining in part the waveguide laser channel extending along the optical axis. The second elongate surface has a non-linear cross-section normal to the optical axis. A dielectric insert may be provided between the electrodes defining in part the waveguide laser channel. A lengthwise gap may extend essentially an entire length of the waveguide laser channel between one of the first and second electrodes and the dielectric insert. The gap provides fluid communication between the waveguide laser channel and a volume outside the waveguide laser channel.

Abstract: A CO2 gas discharge laser includes elongated planar live and ground electrodes vertically spaced and electrically insulated from each. The electrodes are spaced apart by ceramic spacer strips arranged along the edges of the electrodes. An auxiliary electrode is located at each end of the live electrode, co-planar with the live electrode, longitudinally spaced part from the live electrode vertically spaced apart from, but electrically connected to, the ground electrode. The auxiliary electrode has two raised portions spaced apart by a distance less than the distance between inside edges of the ceramic strips. The raised portions of the auxiliary electrode prevent erosion of the ceramic strips by laser radiation generated in the resonator when the laser is operating.

Abstract: A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

Abstract: A lithographic apparatus is disclosed that has a plurality of control circuits, each control circuit arranged to be connected to an associated radiation source of a plurality of radiation sources configured to generate pulses of radiation for projection onto a substrate and each control circuit arranged to control the energy of radiation pulses generated by that associated radiation source.

Abstract: According to aspects of an embodiment of the disclosed subject matter, a line narrowed high average power high pulse repetition laser micro-photolithography light source bandwidth control method and apparatus are disclosed which may comprise a bandwidth metrology module measuring the bandwidth of a laser output flight pulse beam pulse produced by the light source and providing a bandwidth measurement; a bandwidth error signal generator receiving the bandwidth measurement and a bandwidth setpoint and providing a bandwidth error signal; an active bandwidth controller providing a fine bandwidth correction actuator signal and a coarse bandwidth correction actuator signal responsive to the bandwidth error. The fine bandwidth correction actuator and the coarse bandwidth correction actuator each may induce a respective modification of the light source behavior that reduces bandwidth error. The coarse and fine bandwidth correction actuators each may comprise a plurality of bandwidth correction actuators.

Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: An excimer laser includes a chamber for containing laser gas, electrodes in the chamber disposed to excite the laser gas, thereby producing optical emissions, first and second mirrors arranged to form a resonator cavity, and a detector disposed to receive a portion of light transmitted through the first mirror. The first mirror is more reflective than the second mirror.

Abstract: A method and apparatus is disclosed which may comprise: a gas discharge laser system energy controller which may comprise: a laser system energy controller providing a first laser operating parameter control signal based on an error signal related to a value of the output energy of the laser system compared to a target value for output energy and an energy controller model of the value of the first laser operating parameter necessary to change the value of the laser system output energy to the target value; a first laser system operating parameter control signal modifier providing a modification to the first laser system operating parameter control signal based upon a controller signal modification model of the impact of a second laser system operating parameter on the value of the first laser system operating parameter necessary to change the value of the output energy to the target value.

Abstract: A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

Abstract: The present invention provides in one of the embodiments for either a continuous wave (cw) or pulsed alkali laser having an optical cavity resonant at a wavelength defined by an atomic transition, a van der Waals complex within the optical cavity, the van der Waals complex is formed from an alkali vapor joined with a polarizable gas, and a pump laser for optically pumping the van der Waals complex outside of the Lorentzian spectral wings wherein the van der Waals complex is excited to form an exciplex that dissociates forming an excited alkali vapor, generating laser emission output at the wavelength of the lasing transition.

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 narrow-band laser device for exposure apparatus that allows to reduce damage to, and to hence extend the life of, optical elements such as chamber windows, output coupling mirrors or the like. A ring resonator is provided in an amplification stage laser of the narrow-band laser device for exposure apparatus that comprises an oscillation stage laser and an amplification stage laser. An OC, a high reflection mirror and a high reflection mirror are arranged to be offset, for instance, relative to a longitudinal direction axis of discharge electrodes. As a result, the beam width of laser light injected through the OC of the amplification stage laser becomes wider as the beam shifts inside the ring resonator, in each round trip within the ring resonator. The energy density of laser light in the optical elements of the amplification stage laser becomes reduced thereby, thus prolonging the life of the optical elements.

Abstract: A narrow-band discharge excited laser device including a laser chamber having a laser gas sealed therein, a pair of electrodes provided within the laser chamber to face each other with a predetermined distance therebetween, a band-narrowing module having a magnifying prism and a grating and receiving laser light passing through a slit, and a cross-flow fan circulating the laser gas passing between the electrodes, in which a pulsed voltage is applied from a high-voltage power supply to the pair of electrodes to generate electric discharge between the electrodes, and the pair of electrodes have a width of 1 to 2 mm, a ratio between the electrode width and the inter-electrode distance (electrode with inter-electrode distance) being 0.25 to 0.125.

Abstract: A method/apparatus may comprise a seed laser oscillator producing an output which may comprise: a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage receiving the output of the seed laser oscillator which may comprise: a ring power amplification stage; a coherence busting mechanism intermediate the seed laser oscillator and the ring power amplification stage which may comprise a beam splitter separating the seed laser output into a main beam and a beam entering an optical delay path which may have a delay length longer than the coherence length of a pulse in the seed laser output and may have a beam angular offset mechanism offsetting a delayed beam and the main beam.

Abstract: There is disclosed a laser comprising a laser medium comprising H2(1/p) where p is an integer and 1?p?137, a cavity comprising the laser medium, and a power source to form an inverted population in the energy level of H2(1/p). The power source may form excited vibration-rotational levels of H2(1/p) wherein lasing occurs with a stimulated transition from at least one vibration-rotational level to at least another lower-energy-level other than one with a significant Boltzmann population at the cell neutral-gas temperature, wherein the vibration-rotational levels of H2(1/p) comprise the inverted population.

Abstract: A method of recharging an excimer laser Includes opening an outlet in a chamber containing spent laser gas at a first pressure, opening an inlet in the chamber, the inlet in communication with a laser gas container at a second pressure higher than the first pressure, and flowing fresh laser gas into the chamber and removing at least a portion of the spent laser gases from the chamber without using a vacuum pump.

Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: A hardened pump laser comprises a hardened pump chamber that combines the functions of a conventional flash lamp and a conventional laser cavity flow tube. The hardened pump chamber comprises a hardened filter tube and electrodes. The electrodes are sealed to the hardened filter tube. A chamber in the hardened filter tube is filled with gas through the electrodes, then sealed. The hardened pump chamber performs the laser pumping function while further performing filtering and diffusion functions.

Abstract: An excimer laser cavity is disclosed which includes at least one grating-prism (grism) and a wavelength-selective diffraction grating arranged in sequence. The grism grating surface faces the gain medium and produces an expanded beam which is diffracted on the same side of the prism grating surface normal as the incident beam. The expanded diffracted beam is transmitted through a second surface of the grism either to another grating surface of an additional grism or to a wavelength-selective diffraction grating operating in Littrow configuration. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications.

Abstract: An apparatus exposes a substrate via a pattern of a reticle using pulsed light generated by a light source, and includes a controller configured to control the light source so that the oscillation frequency of the light source changes periodically while the apparatus exposes the substrate. The oscillation frequency is the number of times of emission of the light source per unit time.

Abstract: An apparatus/method which may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a seed laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser system output light beam of pulses, which may comprise a ring power amplification stage; a seed injection mechanism.

Abstract: A multi-chambered excimer or molecular halogen gas discharge laser system comprising at least one oscillator chamber and at least one amplifier chamber producing oscillator output laser light pulses that are amplified in the at least one power chamber, having a fluorine injection control system and a method of using same is disclosed, which may comprise: a halogen gas consumption estimator: estimating the amount of halogen gas that has been consumed in one of the at least one oscillator chamber based upon at least a first operating parameter of one of the least one oscillator chamber and the at least one amplifier chamber, and the difference between a second operating parameter of the at least one oscillator chamber and the at least one amplifier chamber, and estimating the amount of halogen gas that has been consumed in the other of the at least one oscillator chamber and the at least one amplifier chamber based upon at least a third operating parameter of the other of the at least one oscillator chamber and

Abstract: An apparatus/method which may comprise: a very high power line narrowed lithography laser light source which may comprise: a solid state seed laser system which may comprise: a pre-seed laser providing a pre-seed laser output; a fiber amplifier receiving the pre-seed laser output and providing an amplified seed laser pulse which may comprise: a pulse having a nominal wavelength outside of the DUV range; a frequency converter converting to essentially the wavelength of the amplifier gain medium; a first and a second gas discharge laser amplifier gain medium operating at different repetition rates from that of the seed laser output; a beam divider providing the amplifier gain mediums with output pulses from the seed laser; a beam combiner combining the outputs of each respective amplifier gain medium to provide a laser output light pulse beam having the pulse repetition rate of the solid state seed laser system.

Abstract: Apparatus and methods are used for controlling electromagnetic radiation pulse duration in a lithographic apparatus. A dividing element is arranged to divide an electromagnetic radiation pulse into a first portion and a second portion. A prism receives, refracts, and subsequently emits the first portion of the electromagnetic radiation pulse. A directing element is arranged to direct the first and second portions of the electromagnetic radiation pulse parallel to a common optical axis. The first portion combines with the second portion to form a combined radiation beam pulse. The combined radiation beam pulse has a longer pulse duration than the divided electromagnetic pulse and experiences no corresponding loss in intensity.

Abstract: A method and apparatus may comprise a line narrowed pulsed excimer or molecular fluorine gas discharge laser system which may comprise a seed laser oscillator producing an output comprising a laser output light beam of pulses which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module within a first oscillator cavity; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, which may comprise a ring power amplification stage.

Abstract: The proposed gas discharge laser comprises extended solid main discharge electrodes, at each of which at least one ultraviolet pre-ionizer is placed, a gas flow area being formed by means of dielectric gas flow guides and the work surfaces of main electrodes and the pre-ionizers being placed outside of the gas flow area for illuminating a space between the main discharge electrodes through a gap defined between the main electrodes and dielectric guides. The proposed invention makes it possible to design a gas discharge laser for a high pulse repetition frequency mode with high-quality laser radiation.

Abstract: In a CO2 laser a pre-ionizer is assembled in a flange configured to be attached to a laser-gas enclosure of the laser over an aperture in a wall of the enclosure. An aperture in the base of the flange is aligned over the aperture in the enclosure wall. The aperture in the pre-ionizer flange is covered by a ceramic membrane. A disc electrode is in contact with the ceramic membrane on a side of the membrane outside of the laser-gas enclosure. An RF potential applied to the disc electrode creates a corona discharge on the side of the ceramic membrane inside the enclosure. The corona discharge ionizes laser gas in the enclosure before RF power is applied to electrodes of the slab laser. A cylindrical ceramic sleeve extends from the membrane for containing the discharge.

Abstract: An opthalmological apparatus (1) comprises a base station (11) having a light source (51) for generating light pulses, and an application head (3) which can be mounted on an eye (2) having a light projector (58) for the focussed projection of the light pulses for punctiform breakdown of eye tissue (22). The application head (3) additionally has movement drivers (57) for moving the light projector (58) in a feed direction and in a first scanning direction. A scanner (52) is arranged in the base station (11) in order to deflect the light pulses in a second scanning direction. In addition, the opthalmological apparatus (1) comprises an optical transmission system for transmitting deflected light pulses from the base station (11) to the application head (3), and for superimposing the light pulses deflected in the second scanning direction onto the movement of the light projector (58) in the first scanning direction.

Abstract: An excimer laser cavity is disclosed which includes at least one grating-prism (grism) and a wavelength-selective diffraction grating arranged in sequence. The grism grating surface faces the gain medium and produces an expanded beam which is diffracted on the same side of the prism grating surface normal as the incident beam. The expanded diffracted beam is transmitted through a second surface of the grism either to another grating surface of an additional grism or to a wavelength-selective diffraction grating operating in Littrow configuration. The laser produces a laser output beam with a narrow spectral linewidth which is suitable, in particular, for lithography applications.

Abstract: In a first aspect, a lithography apparatus may comprise a mask designed using optical proximity correction (OPC), a pulsed laser source, and an active bandwidth control system configured to increase the bandwidth of a subsequent pulse in response to a measured pulse bandwidth that is below a predetermined bandwidth range and increase a bandwidth of a subsequent pulse in response to a measured pulse bandwidth that is above the predetermined bandwidth range. In another aspect an active bandwidth control system may include an optic for altering a wavefront of a laser beam in a laser cavity of the laser source to selectively adjust an output laser bandwidth in response to the control signal. In yet another aspect, the bandwidth of a laser having a wavelength variation across an aperture may be actively controlled by an aperture blocking element that is moveable to adjust a size of the aperture.

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.

Abstract: An apparatus/method may comprise a line narrowed pulsed lithography laser light source which may comprise: a seed pulse providing laser system which may comprise: a first pulsed seed laser producing seed pulses at a rate of X kHz; a second pulsed seed laser producing seed pulses at a rate of X kHz; an amplification system which may comprise: a first amplifier gain system which may comprise a first and a second pulsed gas discharge amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the first seed laser; a second amplifier gain system which may comprise a first and a second pulsed amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the second seed laser.

Abstract: An apparatus and method which may comprise a pulsed gas discharge laser which may comprise a seed laser portion; an amplifier portion receiving the seed laser output and amplifying the optical intensity of each seed pulse; a pulse stretcher which may comprise: a first beam splitter operatively connected with the first delay path and a second pulse stretcher operatively connected with the second delay path; a first optical delay path tower containing the first beam splitter; a second optical delay path tower containing the second beam splitter; one of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors located in the first tower and in the second tower; the other of the first and second optical delay paths may comprise: a plurality of mirrors defining the respective optical delay path including mirrors only in one of the first tower and the second tower.

Abstract: A method/apparatus may comprise operating a line narrowed pulsed excimer or molecular fluorine gas discharge laser system by using a seed laser oscillator to produce an output which may comprise a first gas discharge excimer or molecular fluorine laser chamber; a line narrowing module; a laser amplification stage which may comprise a ring power amplification stage; the method of operation may the steps of: selecting a differential timing between an electrical discharge between a pair of electrodes in the first laser chamber and in the second laser chamber which at the same time keeps ASE below a selected limit and the pulse energy of the laser system output light beam of pulses essentially constant.

Abstract: A method and apparatus may comprise a laser light source system which may comprise a solid state laser seed beam source providing a seed laser output; a frequency conversion stage converting the seed laser output to a wavelength suitable for seeding an excimer or molecular fluorine gas discharge laser; an excimer or molecular fluorine gas discharge laser gain medium amplifying the converted seed laser output to produce a gas discharge laser output at approximately the converted wavelength. The excimer or molecular fluorine laser may be selected from a group comprising XeCl, XeF, KrF, ArF and F2 laser systems. The laser gain medium may comprise a power amplifier. The power amplifier may comprise a single pass amplifier stage, a multiple-pass amplifier stage, a ring power amplification stage or a power oscillator. The ring power amplification stage may comprise a bow-tie configuration or a race track configuration.

Abstract: A light pulse conditioning apparatus has at least first and second curved reflective surfaces that share a common focus and a light-redirecting element disposed between the first and second curved reflective surfaces to redirect at least a portion of an incident light beam toward the second curved reflective surface as a delayed beam portion. A beam-shifting compensating element is disposed between the first curved reflective surface and the light-redirecting element and in the path of the delayed beam portion, for shifting the optical path of the delayed beam portion as it returns toward the light-redirecting element.

Abstract: For exciting a gas laser arrangement with a plurality of HF signals, at least two pulsed HF signals are generated arid at least two electrodes or pairs of electrodes of the gas laser arrangement are supplied with the pulsed HF signals, respectively. At least two of the electrodes or pairs of electrodes are supplied with pulsed HF signals that are phase-shifted with respect to each other.

Abstract: The present invention provides a control system for a modular high repetition rate two discharge chamber ultraviolet gas discharge laser. In preferred embodiments, the laser is a production line machine with a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. Novel control features specially adapted for a two-chamber gas discharge laser system include: (1) pulse energy controls, with nanosecond timing precision (2) precision pulse to pulse wavelength controls with high speed and extreme speed wavelength tuning (3) fast response gas temperature control and (4) F2 injection controls with novel learning algorithm.

Abstract: A discharge excitation type gas laser oscillator has a discharge excitation unit for exciting a laser gas by discharge in a discharge tube to generate induced emission of laser light, a high-frequency power supply unit for supplying power to the discharge tube, and a controller unit for controlling output current of the high-frequency power supply unit.

Abstract: A laser chamber is provided that increases power, initiation, and discharge efficiency over single chamber lasers by providing a multi-fold laser chamber, protrusions, discharge segmentation and inversion techniques.

Abstract: An RF-excited waveguide laser module comprises a first electrode having a first elongate surface defining in part a waveguide laser channel extending along an optical axis, the first elongate surface having a substantially linear cross-section normal to the optical axis. A second electrode has a second elongate surface defining in part the waveguide laser channel extending along the optical axis. The second elongate surface has a non-linear cross-section normal to the optical axis. A dielectric insert may be provided between the electrodes defining in part the waveguide laser channel. A lengthwise gap may extend essentially an entire length of the waveguide laser channel between one of the first and second electrodes and the dielectric insert. The gap provides fluid communication between the waveguide laser channel and a volume outside the waveguide laser channel.

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: An apparatus and method is disclosed which may comprise a high power excimer or molecular fluorine gas discharge laser DUV light source system which may comprise: a pulse stretcher which may comprise: an optical delay path mirror, an optical delay path mirror gas purging assembly which may comprise: a purging gas supply system directing purging gas across a face of the optical delay line mirror. The optical delay path mirror may comprise a plurality of optical delay path mirrors; the purging gas supply system may direct purging gas across a face of each of the plurality of optical delay line mirrors. The purging gas supply system may comprise: a purging gas supply line; a purging gas distributing and directing mechanism which may direct purging gas across the face of the respective optical delay path mirror.

Abstract: The invention is directed to elements used in high power laser lithographic systems operating at below 250 nm, and in particular to elements that have a coating of selected materials to extend lifetime of the elements; and to a method of preparing the extended lifetime elements. The invention is particularly directed to gratings and mirrors that are coated with silicon dioxide, aluminum oxide or fluorinated silicon dioxide. The coatings of the invention attain their extended life as a result of being deposited while being simultaneously bombarded with an energetic ion plasma.