To reduce the size of a magnetic circuit to be provided in a pulse power module for applying a high voltage in the form of a pulse across a pair of discharge electrodes which are disposed in a laser chamber of a gas laser apparatus, the magnetic circuit may include a magnetic core, an insulation member configured to contain a refrigerant flow path therein and cover the periphery of the magnetic core, and a winding wound around the insulation member.

A high-voltage pulse generator may include a number “n” (n is a natural number of not less than 2) of primary electric circuits connected in parallel to one another on the primary side of a pulse transformer, and a secondary electric circuit of the pulse transformer, which is connected to a pair of discharge electrodes disposed in a laser chamber of a gas laser apparatus. The “n” primary electric circuits may include a number “n” of primary coils connected in parallel to one another, a number “n” of capacitors respectively connected in parallel to the “n” primary coils, and a number “n” of switches respectively connected in series to the “n” capacitors. The “n” primary electric circuits may be connected to a number “n” of chargers for charging the “n” capacitors, respectively. The secondary electric circuit may include a number “n” of secondary coils connected in series to one another, and a number “n” of diodes each connected to opposite ends of each of the “n” secondary coils, to prevent a reverse current flowing from the pair of discharge electrodes toward the secondary coils.

A high-voltage pulse generator may include a number “n” (n is a natural number of not less than 2) of primary electric circuits connected in parallel to one another on the primary side of a pulse transformer, and a secondary electric circuit of the pulse transformer, which is connected to a pair of discharge electrodes disposed in a laser chamber of a gas laser apparatus. The “n” primary electric circuits may include a number “n” of primary coils connected in parallel to one another, a number “n” of capacitors respectively connected in parallel to the “n” primary coils, and a number “n” of switches respectively connected in series to the “n” capacitors. The “n” primary electric circuits may be connected to a number “n” of chargers for charging the “n” capacitors, respectively. The secondary electric circuit may include a number “n” of secondary coils connected in series to one another, and a number “n” of diodes each connected to opposite ends of each of the “n” secondary coils, to prevent a reverse current flowing from the pair of discharge electrodes toward the secondary coils.

A radio frequency, RF, slab laser comprising a live electrode (102) and a ground electrode (108) whose inwardly facing surfaces face each other to form a gap for forming a plasma discharge when the live electrode is supplied with a suitable RF drive signal. The electrodes are enclosed in a vacuum space by a vacuum housing (114) with an access aperture (116). The access aperture is sealed with a vacuum flange (70) that comprises an electrically insulating connector. A plurality of hollow conductors (62) are arranged to extend through the vacuum flange into the vacuum space and connect with the live electrode. The hollow conductors connect to the live electrode to supply it with its RF drive signal and also coolant fluid which is distributed through fluid circulation channels (80a, 80b). Coolant fluid is supplied to the live electrode through certain ones of the hollow conductors and taken out by others.

A radio frequency, RF, slab laser comprising a live electrode (102) and a ground electrode (108) whose inwardly facing surfaces face each other to form a gap for forming a plasma discharge when the live electrode is supplied with a suitable RF drive signal. The electrodes are enclosed in a vacuum space by a vacuum housing (114) with an access aperture (116). The access aperture is sealed with a vacuum flange (70) that comprises an electrically insulating connector. A plurality of hollow conductors (62) are arranged to extend through the vacuum flange into the vacuum space and connect with the live electrode. The hollow conductors connect to the live electrode to supply it with its RF drive signal and also coolant fluid which is distributed through fluid circulation channels (80a, 80b). Coolant fluid is supplied to the live electrode through certain ones of the hollow conductors and taken out by others.

There may be provided a laser unit including a display configured to display one or both of electric power consumed by the laser unit and electric energy consumed by the laser unit.

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 oscillation device can prevent a laser medium-circulating pipe from expanding. The laser oscillation device includes a resonator part, which has an introduction port, through which a laser medium is introduced, and a discharge port, from which the laser medium is discharged, and which generates a laser beam, a laser medium-circulating pipe having one end connected to the introduction port, and the other end connected to the discharge port, a blower arranged in the laser medium-circulating pipe, to circulate the laser medium so that the laser medium is introduced from the introduction port to the resonator part, and the laser medium introduced to the resonator part is discharged from the discharge port, and a heat-insulating mechanism which is provided in the laser medium-circulating pipe, to block heat conduction between the laser medium flowing through the laser medium-circulating pipe and the laser medium-circulating pipe.

A laser oscillation device can prevent a laser medium-circulating pipe from expanding. The laser oscillation device includes a resonator part, which has an introduction port, through which a laser medium is introduced, and a discharge port, from which the laser medium is discharged, and which generates a laser beam, a laser medium-circulating pipe having one end connected to the introduction port, and the other end connected to the discharge port, a blower arranged in the laser medium-circulating pipe, to circulate the laser medium so that the laser medium is introduced from the introduction port to the resonator part, and the laser medium introduced to the resonator part is discharged from the discharge port, and a heat-insulating mechanism which is provided in the laser medium-circulating pipe, to block heat conduction between the laser medium flowing through the laser medium-circulating pipe and the laser medium-circulating pipe.

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.