A laser chamber apparatus may include a pipe, an inner electrode extending along a longitudinal direction of the pipe and disposed in a through hole in the pipe, an outer electrode including a contact plate extending along the longitudinal direction of the pipe and being in contact with an outer circumferential surface of the pipe and a ladder section formed of bar members each having one end connected to the contact plate and juxtaposed along a longitudinal direction of the contact plate, and a leaf spring extending along the longitudinal direction of the pipe and configured to press the outer electrode against the pipe. The leaf spring may include leaf spring pieces separated by slits, and the leaf spring pieces may each include a bent section bent along the edge and are configured to press the bar members in a position shifted from the bent sections toward the edge.

A preliminary ionization discharge device used in a laser chamber of a laser apparatus using preliminary ionization includes a dielectric pipe; a preliminary ionization inner electrode provided inside the dielectric pipe; and a preliminary ionization outer electrode provided outside the dielectric pipe. The preliminary ionization outer electrode includes: a contact plate part configured to contact the dielectric pipe; and an elastic part configured to exert a force in a direction in which the contact plate part pushes the dielectric pipe.

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.

A laser chamber for a discharge excited gas laser apparatus may include: a first discharge electrode disposed in the laser chamber; a second discharge electrode disposed to face the first discharge electrode in the laser chamber; a fan configured to flow laser gas between the first discharge electrode and the second discharge electrode; a first insulating member disposed upstream and downstream of a laser gas flow from the first discharge electrode; a metallic damper member disposed upstream of the laser gas flow from the second discharge electrode; and a second insulating member disposed downstream of the laser gas flow from the second discharge electrode.

Discharge electrodes include a cathode and an anode. The anode is disposed to face the cathode in a discharge direction perpendicular to a longitudinal direction of the cathode, and includes an electrode base 1, and a coating layer that covers a portion of a surface of the electrode base. First corners in a cross section perpendicular to the longitudinal direction connect first straight sections formed of first side surfaces that are side surfaces of the electrode base to a first curved section formed of a first discharge surface that is a discharge surface of the electrode base. The first corners are closer to the cathode in the discharge direction than second corners connecting second straight sections formed of second side surfaces that are side surfaces of the coating layer to a second curved section formed of a second discharge surface that is a discharge surface of the coating layer.

A gas laser apparatus according to an aspect of the present disclosure includes a main discharge circuit that supplies main discharge voltage that causes main discharge to a pair of main discharge electrodes, and a pre-ionization circuit that supplies pre-ionization voltage that causes corona discharge to a pre-ionization electrode. The main discharge circuit includes a step-up pulse transformer, a main capacitor and a switch connected to a primary side of the step-up pulse transformer, a first power source that charges the main capacitor, a first capacitor connected in parallel to a secondary side of the step-up pulse transformer, a first magnetic switch connected to the first capacitor, and a peaking capacitor connected in parallel to the first capacitor through the first magnetic switch and to the main discharge electrodes. An interval between start timings of the corona discharge and the main discharge is 30 ns to 60 ns inclusive.

A laser chamber apparatus may include a pipe, an inner electrode extending along a longitudinal direction of the pipe and disposed in a through hole in the pipe, an outer electrode including a contact plate extending along the longitudinal direction of the pipe and being in contact with an outer circumferential surface of the pipe and a ladder section formed of bar members each having one end connected to the contact plate and juxtaposed along a longitudinal direction of the contact plate, and a leaf spring extending along the longitudinal direction of the pipe and configured to press the outer electrode against the pipe. The leaf spring may include leaf spring pieces separated by slits, and the leaf spring pieces may each include a bent section bent along the edge and are configured to press the bar members in a position shifted from the bent sections toward the edge.

To cool a capacitor including a first electrode and a second electrode, a capacitor cooling structure includes: a conducting part electrically connected with the first electrode; an insulating part that has a first surface including a first position and a second surface including a second position, and is connected with the conducting part at the first position; a first fastening part configured to fasten the conducting part and the insulating part to each other; and a cooling part connected with the second position facing the first position, the conducting part and the cooling part being electrically insulated from each other by the insulating part.

To cool a capacitor including a first electrode and a second electrode, a capacitor cooling structure includes: a conducting part electrically connected with the first electrode; an insulating part that has a first surface including a first position and a second surface including a second position, and is connected with the conducting part at the first position; a first fastening part configured to fasten the conducting part and the insulating part to each other; and a cooling part connected with the second position facing the first position, the conducting part and the cooling part being electrically insulated from each other by the insulating part.

A gas laser amplifier includes a housing, discharge electrode pairs, and an optical resonator. The housing includes an entrance window that allows entry of a first laser beam from outside and an exit window that allows exit of the first laser beam amplified. Each of the discharge electrode pairs excites a laser gas supplied between discharge electrodes facing each other in the housing. The optical resonator causes a second laser beam to oscillate with a gain of the excited laser gas in a non-incident state where the first laser beam from outside the housing does not enter the housing through the entrance window. In an incident state where the first laser beam enters the housing through the entrance window, the optical resonator suspends the oscillation of the second laser beam.