A light source apparatus (200) includes a gas discharge stage (210) and a metal fluoride trap (300). The gas discharge stage includes an optical amplifier (206) and a set of optical elements (250, 260). The optical amplifier includes a chamber (211) configured to hold a gas discharge medium (213), the gas discharge medium outputting a light beam. The set of optical elements is configured to form an optical resonator around the optical amplifier. The metal fluoride trap is configured to trap metal fluoride dust generated from the gas discharge stage. The metal fluoride trap includes an electrostatic precipitator (320) and a packed-bed filter (400, 402, 404) disposed around the electrostatic precipitator. The packed-bed filter includes a plurality of beads configured (406, 408) to absorb metal fluoride dust (208).

An optical system for increasing contrast of pulsed laser radiation includes a first polarization setting optical unit for setting an elliptical polarization state of the pulsed laser radiation, and a multipass cell having at least two opposing mirrors. The pulsed laser radiation passes the multipass cell with formation of a plurality of intermediate focus zones. The multipass cell is filled with a gas having an optical nonlinearity that causes an intensity-dependent rotation of an alignment of the elliptical polarization state of the pulsed laser radiation, such that the multipass cell outputs beam portions having differently aligned elliptical polarization states on account of the intensity-dependent rotation. The optical system further includes an optical beam splitting system for splitting the beam portions having differently aligned elliptical polarization states.

A laser apparatus including an optical element made of a CaF.sub.2 crystal and configured to transmit an ultraviolet laser beam obliquely incident on one surface of the optical element, the electric field axis of the P-polarized component of the laser beam propagating through the optical element coinciding with one axis contained in <111> of the CaF.sub.2 crystal, with the P-polarized component defined with respect to the one surface. A method for manufacturing an optical element, the method including causing a seed CaF.sub.2 crystal to undergo crystal growth along one axis contained in <111> to form an ingot, setting a cutting axis to be an axis inclining by an angle within 14.18±5° with respect to the crystal growth direction toward the direction of another axis contained in <111>, which differs from the crystal growth direction, and cutting the ingot along a plane perpendicular to the cutting axis.

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. Once the target values are provided, the process runs quickly without manual interaction.

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. Once the target values are provided, the process runs quickly without manual interaction.

A laser chamber including a first space and a second space in communication with the first space may include: a first discharge electrode disposed in the first space; a second discharge electrode disposed in the first space to face the first discharge electrode; a fan disposed in the first space and configured to flow laser gas between the first discharge electrode and the second discharge electrode; a peaking condenser disposed in the second space; and an electrical insulating member configured to partition the first space and the second space from one another, and disposed to allow the laser gas to pass through between the first space and the second space.

Disclosed are methods and apparatus for generating a sub-200 nm continuous wave (cw) laser. A laser apparatus includes a chamber for receiving at least a rare gas or rare gas mixtures and a pump laser source for generating at least one cw pump laser focused in the chamber for generating at least one laser-sustained plasma in the chamber. The laser apparatus further includes a system for forming an optical cavity in which the at least one laser-sustained plasma serves as an excitation source for producing at least one cw laser having a wavelength that is below about 200 nm. In one aspect, the at least one laser-sustained plasma has a shape that substantially matches a shape of the optical cavity.

A laser oscillation device can prevent a laser medium-circulating pipe from expanding. The laser oscillation device includes a resonator part, which has an introduction port, through which a laser medium is introduced, and a discharge port, from which the laser medium is discharged, and which generates a laser beam, a laser medium-circulating pipe having one end connected to the introduction port, and the other end connected to the discharge port, a blower arranged in the laser medium-circulating pipe, to circulate the laser medium so that the laser medium is introduced from the introduction port to the resonator part, and the laser medium introduced to the resonator part is discharged from the discharge port, and a heat-insulating mechanism which is provided in the laser medium-circulating pipe, to block heat conduction between the laser medium flowing through the laser medium-circulating pipe and the laser medium-circulating pipe.

A gas laser, including: a semiconductor laser, an optical beam-shaping system, a pair of electrodes, a discharge tube, a rear mirror, and an output mirror. The pair of electrodes includes two electrodes. The electrodes are symmetrically disposed at an outer layer of the discharge tube in parallel. The electrodes are connected to a radio-frequency power supply via a matching network, and the electrodes operate to modify working gas in the discharge tube through radio-frequency discharge. The rear mirror and the output mirror are disposed at two end surfaces of the discharge tube, respectively. The rear mirror, taken together with the output mirror and the discharge tube, form a resonant cavity. The output mirror is configured to output a laser beam.

A dielectric electrode assembly, and a method of manufacture thereof, including: a dielectric tube having a cylindrical cross-section and a relative dielectric constant, ε.sub.2, the dielectric tube filled with a gas having a relative dielectric constant, ε.sub.1; a structural dielectric having a relative dielectric constant, ε.sub.3 surrounding the dielectric tube; metal electrodes on opposite sides of the structural dielectric, the metal electrodes having a flat cross-sectional geometry; and the structural dielectric made from a material selected such that the relative dielectric constants of the structural dielectric, the dielectric tube, and the gas are interrelated and a uniform electric field is generated within the dielectric tube when power is applied to the metal electrodes.