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.

Discharge electrodes to be used in a gas laser device for exciting a laser gas containing fluorine by discharge include a cathode and an anode. The anode is arranged as facing the cathode and includes an electrode base member including a metal, and a coating layer including an insulating material and coating a part of a side surface, parallel to a longitudinal direction, of the electrode base member. The coating layer includes a first portion coating a first region of the side surface and a second portion coating a second region of the side surface, located farther from the cathode than the first region in a discharge direction perpendicular to the longitudinal direction, and being thicker than the first portion.

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.

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 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 method and device for limiting the deflection of a laser head during temperature changes such that a laser head is usable in applications of laser technology.