A line narrowing module includes an enclosure, a prism which is disposed in an internal space of the enclosure and through which light passes, a mounter which is disposed in the internal space and on which the prism is mounted, a fixing unit which is disposed in the internal space and fixes the prism to the mounter, and a light blocking member. The light blocking member is disposed in the internal space and blocks scattered light in the internal space, the scattered light produced from the light and traveling to the fixing unit.

An excimer laser chamber device may include: a the laser chamber; a first electrode provided in the laser chamber; a second electrode provided in the laser chamber to face the first electrode; an electrode holder provided in the laser chamber to be connected to a high voltage; at least one connecting terminal including a first anchored portion anchored to the first electrode and a second anchored portion anchored to the electrode holder, the at least one connecting terminal being configured to electrically connect the first electrode and the electrode holder; a guide member held by the electrode holder, the guide member being configured to position the first electrode in a direction substantially perpendicular to both a direction of electric discharge between the first electrode and the second electrode and a longitudinal direction of the first electrode; and an electrode-gap-varying unit configured to move the first electrode in a direction substantially parallel to the direction of electric discharge.

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 laser device may include: a master oscillator including a first laser chamber, a first pair of discharge electrodes provided in the first laser chamber, and an optical resonator, the master oscillator being configured to output a laser beam; a first amplifier including a second laser chamber provided in an optical path of the laser beam outputted from the master oscillator and a second pair of discharge electrodes provided in the second laser chamber at a first gap distance, the first amplifier being configured to amplify the laser beam; and a first beam-adjusting optical system provided in an optical path of the laser beam between the master oscillator and the first amplifier, the first beam-adjusting optical system being configured to adjust the laser beam outputted from the master oscillator such that a beam width of the laser beam entering the first amplifier measured in a direction of electric discharge between the second pair of discharge electrodes is substantially equal to the first gap distance between the second pair of discharge electrodes.

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.

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 processing method of performing laser processing on a transparent material that is transparent to ultraviolet light by using a laser processing system includes: performing relative positioning of a transfer position of a transfer image and the transparent material in an optical axis direction of a pulse laser beam so that the transfer position is set at a position inside the transparent material at a predetermined depth ΔZsf from a surface of the transparent material in the optical axis direction; and irradiating the transparent material with the pulse laser beam having a pulse width of 1 ns to 100 ns inclusive and a beam diameter of 10 μm to 150 μm inclusive at the transfer position.

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.