Abstract: A gas laser oscillator including discharge tubes, main discharge electrodes, auxiliary electrodes, an output mirror which outputs a laser, and a mechanical shutter which cuts off the laser output from the output mirror. To maintain the auxiliary discharge in the state where the laser output is zero, the base discharge command is set to a first command value when the mechanical shutter is closed, and is set to a second command value smaller than the first command value when the mechanical shutter is opened.

Abstract: A gas laser system including: a laser oscillator; a power supply unit for supplying power to the laser oscillator; a power storage unit for storing the power supplied from the power supply unit; a power reduction detection unit for detecting a power reduction state where a value of the power supplied from the power supply unit falls below a power value enabling the laser oscillator to normally operate; and a control unit for controlling the gas supply and discharge unit by using the power stored in the power storage unit so as to seal the gas flow path, when the power reduction detection unit detects the power reduction state.

Abstract: A system and method for automatically performing gas optimization after a refill in the chambers of a two chamber gas discharge laser is disclosed. The laser is fired at low power, and the gas in the amplifier laser chamber bled if necessary until the discharge voltage meets or exceeds a minimum value without dropping the pressure below a minimum value. The power output is increased to a burst pattern that approximates the expected operation of the laser, and the amplifier chamber gas bled again if necessary until the voltage and an output energy meet or exceed minimum values, or until the pressure is less than a minimum value. The gas in the master oscillator chamber is then bled if necessary until the output energy of the master oscillator meets or falls below a maximum value, again without dropping the pressure in the chamber below the minimum value. While the pressure is adjusted, bandwidth is also measured and adjusted to stay within a desired range.

Abstract: Apparatus, systems, and methods using an optically pumped gas filled hollow fiber laser can be implemented in a variety of applications. In various embodiments, operation of an optically pumped gas filled hollow fiber laser is based on population inversion in the gas. Additional apparatus, systems, and methods are disclosed.

Abstract: A laser includes a total reflective mirror, an output mirror, a discharge lamp, and an active laser medium. The total reflective mirror, the output mirror, and the discharge lamp define a resonant cavity. The active laser medium is filled in the resonant cavity. The total reflective mirror includes a body, a metal film, and at least one microstructure. Each of the at least one microstructure is a step structure. The step structure includes a plurality of cylinders stacked with each other with respect to their diameters. Both the height and the diameter of the cylinders are in a range from about 0.5? to about 2?, while ? is a working wavelength of the laser.

Abstract: Singlet oxygen metastables can be formed. A catalytic coating is formed on an interior surface of a flow reactor, and an oxygen containing species is flowed into the flow reactor to produce singlet oxygen metastables by a chemical reaction in the presence of the catalytic coating.

Abstract: An apparatus and method of operation for a high power broad band elongated thin beam laser annealing light source, which may comprise a gas discharge seed laser oscillator having a resonance cavity, providing a seed laser output pulse; a gas discharge amplifier laser amplifying the seed laser output pulse to provide an amplified seed laser pulse output; a divergence correcting multi-optical element optical assembly intermediate the seed laser and the amplifier laser. The divergence correcting optical assembly may adjust the size and/or shape of the seed laser output pulse within a discharge region of the amplifier laser in order to adjust an output parameter of the amplified seed laser pulse output. The divergence correcting optical assembly may comprise a telescope with an adjustable focus. The adjustable telescope may comprise an active feedback-controlled actuator based upon a sensed parameter of the amplified seed laser output from the amplifier laser.

Abstract: The present invention aims to prevent, in a gas laser resonator, the deterioration in quality of discharge by reduction of the change of the pressure in a discharge chamber and the inflow of impurity gases, such as air, into the discharge chamber. A bracket 6 is attached to one end of a tube 1 interposing a gasket 13 only for sealing an opening of the discharge chamber 2 only and a gasket 14 for sealing both openings of the discharge chamber 2 and a buffer chamber 12. Also, a glass plate 8 and further a bracket 9 are attached to the other end of the tube 1 interposing a gasket 15 only for sealing the opening of the discharge chamber 2 and a gasket 16 for sealing both openings of the discharge chamber 2 and the buffer chamber 12. The pressure in the buffer chamber 12 is set lower than that of the discharge chamber 2 or set higher than the atmospheric pressure to decrease the inflow of the impurity gases to the discharge chamber 2.

Abstract: A laser apparatus includes a master oscillator capable of outputting a laser beam having a spectrum that includes at least three wavelength peaks, a multi-wavelength oscillation control mechanism capable of controlling energy of each of the wavelength peaks, a spectrum detecting unit that detects the spectrum of the above-mentioned laser beam, and a controller that controls the multi-wavelength oscillation control mechanism based on a detection result detected by the spectrum detecting unit.

Abstract: A gas includes a housing having a symmetrical arrangement of upper and lower cooling members for removing heat generated in a gas-discharge excited by an electrode assembly. The electrode assembly is clamped between the cooling members and is itself essentially symmetrically arranged. The cooling members and the electrode assembly are mechanically isolated in the housing by a surrounding diaphragm-like arrangement that connects the cooling members to side-walls of the housing. An RF power-supply for supplying the electrode assembly is mounted on one of the sidewalls to avoid disturbing the symmetry of the cooling and electrode arrangements.

Abstract: A blower apparatus includes a blower casing; an elastic member for mounting a mounting portion that projects on an outer circumferential portion of the blower casing, to a blower support member disposed on the inlet side of the mounting portion; and a flange portion provided on the inlet side of the mounting portion. At least three elastic members are disposed in the same plane that is almost orthogonal to a rotation shaft, and adhesion surfaces are provided on both ends, in the rotation shaft direction, of each elastic member. The mounting portion is fixed to one of the adhesion surfaces, and the blower support member is fixed to the other of the adhesion surfaces. The flange portion is provided so as to oppose the blower support member through a gap having a thickness less than a thickness, in the rotation shaft direction, of the elastic member.

Abstract: Subject matter of the invention is a CO2 laser that permits a rapid power modulation, particularly a highly efficient Q-switching. The key concept is the sub-division of the resonator into a high-power branch, containing inter alia the active medium (1), and a low-power feedback branch (14), in which the power-sensitive beam-shaping elements, particularly the modulators, are arranged. This is made possible by a suitable arrangement of a polarisation beam splitter (5) and a ?/4-phase shifter (2). The free adjustability of an angle ? between said two components permits the extremely flexible realisation of various operating modes, particularly the optimisation of the feedback degree during pulse generation.

Abstract: A gas laser oscillator, including a power supply part supplying a discharge tube voltage corresponding to a power output command to a discharge tube so as to start a discharge in the discharge tube; a voltage detecting part detecting the discharge tube voltage; a current detecting part detecting an output current of the power supply part; a command voltage control part gradually increasing a power output command value output from the output command part; and a discharge start judgment part judging if the discharge in the discharge tube has started, based on a detected value of the voltage detecting part when gradually increasing the power output command value. The command voltage control part, if the output current becomes a predetermined threshold value or more when gradually increasing the power output command value, decreases the power output command value once, then again gradually increases the power output command value.

Abstract: In a slab laser, a gas mixture containing carbon dioxide CO2 is formed as a laser-active medium in a discharge space which is formed between two plate-shaped metal electrodes, the flat faces of which are located opposite one another. A resonator mirror is arranged on each of the mutually opposite end faces of the discharge space, the mirrors forming an unstable resonator parallel to the flat faces. At least one of the mutually facing flat faces is provided either on the entire flat face with a dielectric layer the thickness of which is greater on at least one sub-surface than in the remaining area of the flat face, or the at least one flat face is provided with a dielectric layer exclusively on at least one sub-surface.

Abstract: A degree of polarization control device includes: a calcium fluoride crystal substrate for transmitting a laser beam; a polarization monitor for measuring the degree of polarization of a laser beam transmitted through the calcium fluoride crystal substrate; and a controller for controlling the rotation angle of the calcium fluoride crystal substrate according to the degree of polarization measured by the polarization monitor; the calcium fluoride crystal substrate being formed by a flat plate having a laser beam entering surface and a laser beam exiting surface running in parallel with the (111) crystal face, the Brewster angle being selected for the incident angle, the rotation angle around the [111] axis operating as a central axis being controlled by the controller.

Abstract: A carbon dioxide slab laser includes a top electrode and a bottom electrode. The top electrode has a socket formed at a geometric center and receives a contact ring in the recess of the socket. The contact ring includes radially inward extending biasing fingers. The biasing fingers contact a radio frequency (RF) energy feed through plug and engages the outer wall of the plug and retains it in the socket. The fingers disperse RF energy radially outward to the laser and provide for more even energy distribution that allows for more power. Grounding is also improved through grounding bars spaced apart longitudinally along the length of the bottom electrode. The transverse extending bars include contact elements having spaced apart fingers along the length of the contact element and providing multiple ground points to prevent focusing at a single grounding point.

Abstract: Upon starting the lasing device after having a stop state, gas retaining in the gas circulation path and the optical resonator is released through the gas release valve opened by the gas pressure controller. During a time calculated by the open-time calculator in response to the immediately preceding stop time of the lasing device, laser medium gas in the piping between the laser medium gas supply device and the gas supply valve is released, together with the retaining gas, through the gas supply valve opened by the gas pressure controller. The structure reduces costs by using decreased number of valves and suppresses consumption of laser medium gas.

Abstract: Efficient laser diode excited Thulium (Tm) doped solid state systems, directly matched to a combination band pump transition of Carbon Dioxide (CO2), have matured to the point that utilization of such in combination with CO2 admits effectively a laser diode pumped CO2 laser. The laser diode excited Tm solid state pump permits Continuous Wave (CW) or pulsed energy application. Appropriate optical pumping admits catalyzer free near indefinite gas lifetime courtesy of the absence of significant discharge driven dissociation and contamination. As a direct consequence of the preceding arbitrary multi isotopologue CO2, symmetric and asymmetric, gas mixes may be utilized without significant degradation or departure from initial mix specifications. This would admit, at raised pressure, a system continuously tunable from approximately 9 ?m to approximately 11.5 ?m, or sub picosecond amplification.

Abstract: A degree of polarization control device includes: a calcium fluoride crystal substrate for transmitting a laser beam; a polarization monitor for measuring the degree of polarization of a laser beam transmitted through the calcium fluoride crystal substrate; and a controller for controlling the rotation angle of the calcium fluoride crystal substrate according to the degree of polarization measured by the polarization monitor; the calcium fluoride crystal substrate being formed by a flat plate having a laser beam entering surface and a laser beam exiting surface running in parallel with the (111) crystal face, the Brewster angle being selected for the incident angle, the rotation angle around the [111] axis operating as a central axis being controlled by the controller.

Abstract: A CO2 laser device and a CO2 laser processing device for emitting a pulse laser having a high output and a stable beam diameter without depending on a repetition frequency. The CO2 laser device includes: laser gas being a CO2 laser medium; a near-concentric stable optical resonator in which a radius of curvature of at least one resonator mirror is set so as to be equal to a distance from an optical switch to the resonator mirror; an optical switch provided in the stable optical resonator; and transmission mirrors provided so that laser light generated from the stable optical resonator passes through the CO2 laser medium again.

Abstract: A CO2 gas laser device according to the present invention amplifies CO2 laser light that oscillates repeatedly in short pulses having a pulse width of 100 ns or less, and cools a CO2 laser gas which is excited by continuous discharge by circulating the CO2 laser gas by means of forced convection. Therein, an angle ? defined by the optical axis of the amplified CO2 laser beam and the flow direction of the CO2 laser gas caused by the forced convection is determined by both a discharge cross sectional area and a discharge length of a volume in which the CO2 laser gas is excited by discharge, whereby increasing the gain of pulsed laser to achieve pulsed laser light having an extremely high average output power.

Abstract: When a chamber of an oscillator and one or more amplifiers is to be replaced at the timing when a predetermined period elapses, one of the chambers of the oscillator and the amplifiers having a low allowable deterioration limit is detached and this chamber is attached in place of one of the chambers of the oscillator and the amplifiers other than the one having the low allowable deterioration limit. Thus, the chamber which has been used in one of the oscillator and amplifiers having a low allowable deterioration limit and has not reached the limit of deterioration is reused in one of the oscillator and the amplifiers other than the one having the low allowable deterioration limit. This enables efficient use of oscillator and amplifier chambers in a multistage amplification laser apparatus, minimizing the labor and parts consumed for replacement thereof.

Abstract: Systems and methods for automatically performing a high accuracy gas refill in a laser chamber of a two chamber gas discharge laser such as an excimer laser are disclosed. Based upon a target pressure and halogen concentration that is either predetermined or entered by a user, and with no further user action, a non-halogen containing gas is added to the chamber to a first pressure, followed by the addition of halogen containing gas to a second pressure which is greater than a target pressure for the chamber, such that the halogen content in the gas at the second pressure is at a desired concentration. The gas in the chamber is bled until the pressure drops to the target pressure. The amount of non-halogen containing gas added is estimated automatically, and the amount of halogen containing gas is measured so that the desired concentration is obtained, taking into account both temperature and any gas remaining in the fill pipes from prior laser operation.

Abstract: An excimer laser apparatus includes a gas supply unit, connected to a first receptacle that holds a first laser gas containing halogen gas and a second receptacle that holds a second laser gas having a lower halogen gas concentration than the first laser gas, that supplies the first laser gas and the second laser gas to the interior of the laser chamber. Gas pressure control in which the gas supply unit supplies the second laser gas to the interior of the laser chamber or a gas exhaust unit partially exhausts gas from within the laser chamber, and partial gas replacement control in which the gas supply unit supplies the first laser gas and the second laser gas to the interior of the laser chamber and the gas exhaust unit partially exhausts gas from within the laser chamber sequentially, may be selectively performed.

Abstract: A laser apparatus may include: a first module including an oscillator configured to output a laser beam and an oscillator support portion for supporting the oscillator; a second module including a beam delivery unit for delivering the laser beam and a beam delivery unit support portion for supporting the beam delivery unit; a third module including an amplifier for amplifying the laser beam and an amplifier support portion for supporting the amplifier; and a frame on which the modules are placed, the frame including mounts on which the oscillator support portion, the beam delivery support portion and the amplifier support portion are placed.

Abstract: A gas discharge chamber that uses a calcium fluoride crystal which reduces a breakage due to mechanical stress (window holder and laser gas pressure), thermal stress from light absorption, and the like, increases the degree of linear polarization of output laser, and suppresses degradation due to strong ultraviolet (ArF, in particular) laser light irradiation. A first window (2) and a second window (3) of the gas discharge chamber have an incident plane and an emitting plane in parallel with a (111) crystal plane of their calcium fluoride crystal. With respect to an arrangement where laser light entering the calcium fluoride crystal passes through a plane including a <111> axis and a <001> axis of each of the first window (2) and the second window (3) as seen from inside the chamber (1), the first window (2) and the second window (3) are arranged in positions rotated in the same direction by the same angle about their <111> axis.

Abstract: A laser includes a total reflective mirror, an output mirror, a discharge lamp, and an active laser medium. The total reflective mirror, the output mirror, and the discharge lamp define a resonant cavity. The active laser medium is filled in the resonant cavity. The total reflective mirror includes a body, a metal film, and at least one microstructure. Each of the at least one microstructure is a step structure. The step structure includes a plurality of cylinders stacked with each other with respect to their diameters. Both the height and the diameter of the cylinders are in a range from about 0.5? to about 2?, while ? is a working wavelength of the laser.

Abstract: A gas-discharge waveguide CO2 laser has a Z-shaped folded waveguide formed by three ceramic tubes. Ends of the adjacent tubes are shaped and fitted together to form a common aperture. The tubes are held fitted together by spaced-apart parallel discharge electrodes. Four minors are arranged to form a laser-resonator having a longitudinal axis extending through the tubes.

Abstract: An RF power-supply for driving a carbon dioxide CO2 gas-discharge laser includes a plurality of power-oscillators phase-locked to a common reference oscillator. Outputs of the phase-locked power-oscillators are combined by a power combiner for delivery, via an impedance matching network, to discharge-electrodes of the laser. In one example the powers are analog power-oscillators. In another example, the power-oscillators are digital power-oscillators.

Abstract: Continuous mass flow gas replenishment may be implemented in a gas lasing device, such as a gas laser or amplifier, by using a restrictive orifice to bleed one or more gases into a reservoir and/or discharge chamber of the gas laser or amplifier at a predefined mass flow rate. The mass flow rate is a function of the pressure drop across the restrictive orifice resulting from the pressure differential between the depleted gas and the source gas. Thus, gases may be added as needed such that the gas total pressure, as well as the constituent partial pressures, is maintained within a desired range throughout the laser or amplifier fill lifetime. The continuous mass flow gas replenishment may thus make up the lost partial pressure of reactive gases in gas lasing devices in a manner that is less complicated and is less expensive than other continuous flow methodologies.

Abstract: The invention refers to a laser device comprising a plurality of linear resonator tubes (12) for a gas to be excited, the resonator tubes being in fluidic communication with each other and forming a common tubular space, connecting elements (20) arranged in corners between adjacent resonator tubes of a common tubular space, excitation means (50) for the resonator tubes for exciting the gas in the resonator tubes for generating a laser light, mirrors (22) arranged in the connecting elements for reflecting laser light between the resonator tubes, and a partially reflecting output coupler (42) for coupling out a laser beam. The resonator tubes are arranged in the shape of a helix, surrounding a free central space. The invention also relates to a method for generating laser light with such a laser device.

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 laser device, which includes an oscillator unit having a rectangular-solid-shaped housing containing a laser oscillator for generating and outputting a laser light; an amplifier unit having a rectangular-solid-shaped housing containing an amplifier that receives and amplifies the laser light to output; and, a group of optical elements including optical elements provided on a laser light path, wherein the laser device includes one or more amplifier units, and the oscillator and the amplifier units are arranged such that surfaces having a wide area other than a surface having a smallest area of a housing of the oscillator unit and a housing of at least one amplifier unit are next to and face each other, or such that surfaces having a wide area other than a surface having a smallest area of a housing of at least two amplifier units are next to and face each other.

Abstract: The invention relates to a laser device comprising at least three linear laser gain volumes (12) for a gas to be excited, connecting elements (20) for connecting adjacent laser gain volumes, the laser gain volumes being mechanically coupled to other, and forming a common volumetric space, excitation means (50) for the laser gain volumes for exciting the gas in the laser gain volumes for generating a laser light, mirrors (22) arranged in the connecting elements for reflecting laser light between the laser gain volumes, a totally reflecting rear mirror (44), and a partially reflecting output coupler (42) for coupling out a laser beam. The laser gain volumes are arranged in the shape of an open or closed ring surrounding a free central space (8) between them. The invention also relates to a method for marking an object.

Abstract: The gas laser oscillator apparatus of the present invention has laser gas sealed in a vacuum chamber under a decompressed condition lower than atmospheric pressure; a discharge means for exciting the laser gas; a blower means for blowing the laser gas; a laser-gas flow passage as a circulation passage of the laser gas between the discharge means and the blower means; and a gas compression means for discharging a predetermined amount of the laser gas from the laser-gas flow passage. The gas decompression means is structured on the application of Bernoulli's principle. The gas decompression means has a sequence for decreasing the ratio of air mixed into the laser gas below a predetermined level with use of a part of pressurized gas used in a laser processing machine or the gas laser oscillator apparatus.

Abstract: A temperature controller for a gas laser which controls temperatures of a plurality of temperature-controlled apparatuses including a first temperature-controlled portion requiring a high-precision temperature-control and a second temperature-controlled portion requiring a low-precision temperature-control as compared with the first temperature-controlled portion and allowing a temperature-control with a low or high temperature as compared with the first temperature-controlled portion, comprises a first temperature control portion generating a cooling agent or a heating agent for adjusting a temperature of each first temperature-controlled portion, a second temperature control portion generating a cooling agent or a heating agent for adjusting a temperature of each second temperature-controlled portion, a first piping system connecting the first temperature control portion and each first temperature-controlled portion in parallel, and a second piping system connecting the second temperature control portion an

Abstract: An optically pumped sulfur monoxide (SO) molecular laser is presented. A near infrared pump light source generates a pump light at wavelengths that match wavelengths of a Q-branch or R-branch absorption transition of a b 1?+ excited electronic state of the SO molecule. The pump light is directed to a vessel containing a laser gain medium including gaseous SO and a buffer gas. The gaseous gain medium may be flowed through the region of output light extraction to remove waste heat deposited in the medium. In some examples output light is generated from any of the R-branch, Q-branch, or P-branch emission transitions between the v=0 vibrationless b 1?+ electronic state and the v=1 vibrational x 3?? ground electronic state. In some other examples, output light is generated from P-branch emission transitions between the v=0 vibrationless b 1?+ electronic state and the v=0 vibrationless x 3?? ground electronic state.

Abstract: A thin beam laser crystallization apparatus for selectively melting a film deposited on a substrate is disclosed having a laser source producing a pulsed laser output beam, the source having an oscillator comprising a convex reflector and a piano output coupler; and an optical arrangement focusing the beam in a first axis and spatially expanding the beam in a second axis to produce a line beam for interaction with the film.

Abstract: An upper limit and a lower limit are preliminarily set for a spectral line width common to a plurality of narrow-band laser devices. When delivered or subjected to maintenance, the narrow-band laser device is caused to laser oscillate to detect its spectral line width before it is used as a light source for semiconductor exposure. A spectral line width adjustment unit provided in the narrow-band laser device is adjusted so that the spectral line width assumes a value between the upper limit and the lower limit. The present invention is able to suppress the variation in spectral line width such as E95 bandwidth caused by machine differences during the manufacture of the laser device, or by replacement or maintenance of the laser device, whereby the quality of integrated circuit patterns formed by the semiconductor exposure tool can be stabilized.

Abstract: A method for providing a laser beam and a laser arrangement that includes an elongated tube; an elongated discharge region within the elongated tube including a discharge medium to be excited to induce laser radiation; two DC discharge electrodes disposed at opposite ends of the elongated discharge region; two RF electrodes disposed at opposite elongated sides of the elongated discharge region; and/or a laser resonator having two opposite mirrors disposed at opposite ends of the elongated tube, the laser resonator is unstable in at least one lateral axis. The method includes applying a DC discharge between the DC electrodes, and applying a RF discharge transverse to the DC discharge between the RF electrodes. The DC and RF discharges may be provided by the DC and/or RF voltage suppliers provided according to embodiments of the present invention.

Abstract: A gas laser oscillator includes a discharge section for exciting laser gas, a blowing section for transmitting the laser gas, and a laser gas flowing path for forming a circulation route of the laser gas between the discharge section and the blowing section. The blowing section is formed of a rotary part to be rotated by a shaft driver and a non-rotary part not to be rotated. The rotary part includes a rotary shaft to which an impeller is mounted at an end, the shaft driver for rotating the rotary shaft, an upper bearing and a lower bearing coupled to the rotary shaft. The rotary part is detachable from the non-rotary part.

Abstract: Singlet oxygen metastables can be formed. A catalytic coating is formed on an interior surface of a flow reactor, and an oxygen containing species is flowed into the flow reactor to produce singlet oxygen metastables by a chemical reaction in the presence of the catalytic coating.

Abstract: Methods and systems for controlling the gas concentrations in the chambers of a two chamber gas discharge laser such as an excimer laser are disclosed. A first set of inject opportunities is selected for the laser chamber of the master oscillator, and a second set of inject opportunities is selected for the laser chamber of the power amplifier. At each selected inject opportunity for the master oscillator, its laser chamber receives an inject containing a fixed amount of a non-halogen containing gas, and a calculated amount of a halogen containing gas. At the selected inject opportunities for the power amplifier, its laser chamber receives a fixed amount of the halogen containing gas, and may also receive a fixed amount of the non-halogen containing gas.

Abstract: A laser oscillation device includes an oscillation unit oscillating a laser, a shutter unit covering the laser, and a connection unit covering the laser, connecting the oscillation unit and the shutter unit and including a first connection part supported by the oscillation unit and a second connection part supported by the shutter unit. The first and second connection parts are separated from each other, and one of the first and second connection parts covers at least a portion of the other one of the first and second connection parts.

Abstract: A compact CO2 slab-laser is contained in a fluid cooled housing having three compartments. One compartment houses discharge electrodes and a laser resonator. Another compartment houses a radio-frequency power supply (RFPS) assembled on a fluid-cooled chill plate and an impedance-matching network. The remaining compartment houses beam-conditioning optics including a spatial filter. The housing and RFPS chill-plate are on a common coolant-fluid circuit having a single input and a single output. The spatial filter is optionally fluid-coolable on the common coolant fluid circuit.

Abstract: An EUV light source is disclosed which may comprise a plurality of targets, e.g., tin droplets, and a system generating pre-pulses and main-pulses with the pre-pulses for irradiating targets to produce expanded targets. The system may further comprise a continuously pumped laser device generating the main pulses with the main pulses for irradiating expanded targets to produce a burst of EUV light pulses. The system may also have a controller varying at least one pre-pulse parameter during the burst of EUV light pulses. In addition, the EUV light source may also include an instrument measuring an intensity of at least one EUV light pulse within a burst of EUV light pulses and providing a feedback signal to the controller to vary at least one pre-pulse parameter during the burst of EUV light pulses to produce a burst of EUV pulses having a pre-selected dose.

Abstract: An unstable optical resonator device is provided, comprising a spherical back mirror, a spherical outcoupling mirror, wherein a focal point lies between the back mirror and the outcoupling mirror, an optically active medium with a rectangular medium cross-section arranged between the back mirror and the outcoupling mirror, and a scraper, which is arranged between the back mirror and the outcoupling mirror and has a first leg and a second leg located transversely to the first leg, said legs defining a free space with a first side delimited by the first leg and a second side delimited by the second leg, wherein the first side and the second side are orthogonal to one another.

Abstract: A laser system in this disclosure may include: a master oscillator configured to output pulsed laser light, a coherence reduction optical system configured to reduce coherence of the pulsed laser light from the master oscillator, and a controller configured to control the coherence reduction optical system so that a speckle of the pulsed laser light varies.

Abstract: Singlet oxygen metastables can be formed. A catalytic coating is formed on an interior surface of a flow reactor, and an oxygen containing species is flowed into the flow reactor to produce singlet oxygen metastables by a chemical reaction in the presence of the catalytic coating.

Abstract: A laser pulse from an ultrashort pulse laser (USPL) is fired into the atmosphere. The USPL pulse is configured to generate a plasma filament at a predefined target in the atmosphere, in which free, or “seed,” electrons are generated by multi-photon or tunneling ionization of the air molecules in the filament. A second pulse is fired into the atmosphere to form a heater beam that impinges on the plasma filament and thermalizes the seed electrons within the plasma filament, leading to the collisional excitation of the electrons in the filament. The excited electrons collisionally excite various electronic and vibrational states of the air molecules in the filament, causing population inversions and lasing, e.g., exciting the C3?u?B3?g(v=0?0) transition of the N2 in the atmosphere to cause lasing at 337 nm.