An optical member is provided with a substrate and a Cu-proof protective layer formed on or above the substrate.

A copper electrode material comprising Cu and unavoidable impurities, wherein the content of the unavoidable impurities is 1 ppm by mass or less and the average crystal grain diameter is 100 m or less. A copper-containing electrode material having improved corrosion resistance is provided by the copper electrode material.

A microwave excited gas slab laser comprising a waveguide wherein the electrodes are covered with multi-layered stripes either forming a photonic band-gap or having a refractive index lower than 1.

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 discharge electrode according to an aspect of the present disclosure is for use in a gas laser apparatus that excites a laser gas containing fluorine by discharge, and includes a cathode electrode that extends in one direction, and an anode electrode that extends in the one direction and that is disposed facing the cathode electrode in a discharge direction orthogonal to the one direction. At least one of the cathode electrode and the anode electrode includes an electrode substrate containing a metal, and a dielectric including a first layer having voids provided on a pair of side faces of the electrode substrate. A porosity of the first layer is in a range of 0.5% to 25%.

A chamber for a gas laser device includes a first main electrode and a second main electrode arranged along a predetermined direction as being apart from and facing each other in the internal space, a window arranged at a wall surface of the chamber and transmitting light from the internal space, and a first preionization electrode arranged beside one side of the first main electrode. Here, the first preionization electrode includes a first dielectric pipe, a first preionization inner electrode arranged in the first dielectric pipe and extending along the first dielectric pipe, and a first preionization outer electrode extending along the first dielectric pipe and including a first end portion facing the first dielectric pipe with a first gap with respect to the first dielectric pipe. At least a part of the first gap is larger than 0 mm and equal to or smaller than 0.9 mm.

A laser chamber according to an aspect of the present disclosure is a laser chamber including a pair of electrodes disposed so as to face each other in a first direction, the laser chamber being configured such that a laser gas can be introduced into the laser chamber, at least one of the pair of electrodes including a discharge section extending in a second direction perpendicular to the first direction, and a shoulder section disposed so as to surround a side surface of the discharge section, a surface of the discharge section having a discharge surface extending in the second direction and an end surface provided at an end portion of the discharge section in the second direction, the end surface being a portion of a spheroid.

There is provided a laser system having a cylindrically-shaped annular mirror with at least one opening in its surface; a pair of planar metallic electrodes disposed proximate opposite edges of the annular mirror, normal to the axis of the annular mirror, the electrodes configured to have an RF field applied between them; a pair of end mirrors disposed at said at least one opening; and a ceramic material in the form of a disc, disposed in the internal volume of the annular mirror, the ceramic material having a series of channels formed therein such that they generate a zig-zag pathway in the ceramic material, wherein (i) the zig-zag path, when filled with a gain medium, (ii) the annular mirror and (iii) the pair of end mirrors, together constitute a laser cavity.

A laser chamber includes a cathode electrode including a cathode discharge surface extending in a first direction, an anode electrode including an anode discharge surface extending in the first direction, the anode discharge surface facing the cathode discharge surface in a second direction orthogonal to the first direction, a fan that circulates the laser gas to pass through a discharge space between the cathode electrode and the anode electrode in a third direction orthogonal to the first direction and the second direction, and a preionization electrode disposed on an upstream side of the laser gas. A cross-sectional shape of the cathode discharge surface cut along a plane orthogonal to the first direction is asymmetrical about an axis parallel to the second direction, and a cross-sectional shape of the anode discharge surface cut along the plane is symmetrical about the axis, in an initial state.

Disclosed is an electrode for a laser chamber comprising an alloy of a first metal having a first free energy of formation with fluorine greater than or equal to the free energy of formation with fluorine of copper, and a second metal having a second free energy of formation with fluorine less than the first free energy.