A laser chamber of an excimer laser apparatus includes a container including a first member and a second member and configured to accommodate a laser gas in the container and a seal member disposed between two seal surfaces facing each other, a seal surface of the first member and a seal surface of the second member. A laser-gas-side surface of the seal member is made of fluorine-based rubber, and an atmosphere-side surface of the seal member is formed of a film configured to suppress atmosphere transmission.

A polarisation and mode selection technique for a gas waveguide laser is described in which a surface of the waveguide is formed to be substantially dielectric with a localised metallic region therein. The metallic region provides linear polarisation while the dielectric surface provides for low order mode selection. Embodiments are described to channel and planar waveguides with various resonator configurations. Ranges are provided for the size and location of the metallic region on the waveguide surface.

A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include fluid coolant channels. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.

A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include any direct fluid-cooling means. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.

A light emitting sealed body includes: a housing which stores a discharge gas and is provided with a first opening to which first light is incident along a first optical axis and a second opening from which second light is emitted along a second optical axis; a first window portion which hermetically seals the first opening; and a second window portion which hermetically seals the second opening. The housing is formed of a light shielding material which does not transmit the first light and the second light. An internal space is defined by the housing, the first window portion, and the second window portion and the internal space is filled with the discharge gas. The first opening and the second opening are disposed so that the first optical axis and the second optical axis intersect each other.

A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include any direct fluid-cooling means. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.

In at least one illustrative embodiment, a laser may include a ceramic body defining a chamber containing a laser gas. The chamber may include first and second slab waveguide sections extending along parallel first and second axes and a third slab waveguide section extending along a perpendicular third axis. Respective first ends of the first and second slab waveguide sections may be positioned adjacent opposite ends of the third slab waveguide section. The laser may also include first and second end mirrors positioned at respective second ends of the first and second slab waveguide sections, a first fold mirror positioned near an intersection of the first and third axes at a 45-degree angle to both the first and third axes, and a second fold mirror positioned near an intersection of the second and third axes at a 45-degree angle to both the second and third axes, such that the first, second, and third slab waveguide sections waveguide recirculating light that is polarized orthogonal to a plane defined by the first, second, and third axes.

A polarisation and mode selection technique for a gas waveguide laser is described in which a surface of the waveguide is formed to be substantially dielectric with a localised metallic region therein. The metallic region provides linear polarisation while the dielectric surface provides for low order mode selection. Embodiments are described to channel and planar waveguides with various resonator configurations. Ranges are provided for the size and location of the metallic region on the waveguide surface.

A gas laser device may include: a laser chamber containing laser gas; a first discharge electrode disposed in the laser chamber; a second discharge electrode disposed to face the first discharge electrode in the laser chamber; and a condenser including a polyimide dielectric and configured to supply power to between the first discharge electrode and the second discharge electrode.

There is provided a cylinder including a first cylinder having an inner surface exposed; and a second cylinder joined to an outer surface of the first cylinder, the second cylinder containing alumina as a main component, the first cylinder containing yttrium-containing oxide as a main component.