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 radio-frequency excited carbon dioxide (CO.sub.2) or carbon monoxide (CO) gas laser includes two electrodes, which have passivated surfaces, within a sealed housing. Features in a ceramic slab or a ceramic cylinder located between the electrodes define a gain volume. Surfaces of the ceramic slab or the ceramic cylinder are separated from the passivated surfaces of the electrodes by small gaps to prevent abrasion thereof. Reducing compressive forces that secure these components within the housing further reduces abrasion, thereby extending the operational lifetime of the gas laser.

A multi-pass coaxial molecular gas laser is described in both symmetrical and asymmetrical configuration. An anode vessel receives lasing gas and the gas flows through one or more plasma channels to a cathode vessel which receives the gas and redirects it in the closed system. A second anode vessel may alternatively be provided to double length of the plasma channel and increase surface area exposure of the optical beam to the energized gas. Non-laminar gas flow may be created using spiral nozzles at the entrance of the optical resonator.

A light source apparatus includes an airtight container having a hemispherical or semielliptical first curved portion configured to receive laser light, a hemispherical or semielliptical second curved portion opposite to the first curved portion, and a cylindrical portion connecting the first curved portion and the second curved portion; assist gas sealed in the airtight container; and a light source configured to irradiate laser light to the first curved portion from outside of the airtight container.

A laser chamber may include a first discharge electrode, a second discharge electrode, a fan making a laser gas flow through a discharge space between the first and second discharge electrodes, a first insulating member disposed on upstream side and downstream side of the first discharge electrode in the laser gas flow, a first metal damper member disposed on upstream side of the second discharge electrode and a second insulating member disposed on downstream side of the second discharge electrode in the laser gas flow, and a second metal damper member disposed on downstream side of the second insulating member in the laser gas flow. In a boundary portion between the second metal damper member and the second insulating member, a first discharge space side surface of the second metal damper member may be located further toward the opposite side to the discharge space than a second discharge space side surface of the second insulating member. A first corner formed by the first surface and a first side surface of the second metal damper member, the first side surface being on the side of the second insulating member, may be in contact with a second side surface of the second insulating member, the second side surface being on the side of the second metal damper member.

A light source apparatus includes an airtight container having a hemispherical or semielliptical first curved portion configured to receive laser light, a hemispherical or semielliptical second curved portion opposite to the first curved portion, and a cylindrical portion connecting the first curved portion and the second curved portion; assist gas sealed in the airtight container; and a light source configured to irradiate laser light to the first curved portion from outside of the airtight container.

A laser oscillator which can effectively remove scattered light by a simpler configuration. The laser oscillator comprises an output mirror and a rear mirror which are arranged facing each other and a discharge tube which is arranged between the output mirror and the rear mirror. The discharge tube has a first part which gets larger in inner diameter from a first end part in an axial direction facing the output mirror toward the rear mirror.

A laser chamber may include a first discharge electrode, a second discharge electrode, a fan making a laser gas flow through a discharge space between the first and second discharge electrodes, a first insulating member disposed on upstream side and downstream side of the first discharge electrode in the laser gas flow, a first metal damper member disposed on upstream side of the second discharge electrode and a second insulating member disposed on downstream side of the second discharge electrode in the laser gas flow, and a second metal damper member disposed on downstream side of the second insulating member in the laser gas flow. In a boundary portion between the second metal damper member and the second insulating member, a first discharge space side surface of the second metal damper member may be located further toward the opposite side to the discharge space than a second discharge space side surface of the second insulating member. A first corner formed by the first surface and a first side surface of the second metal damper member, the first side surface being on the side of the second insulating member, may be in contact with a second side surface of the second insulating member, the second side surface being on the side of the second metal damper member.

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.