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 rectangular electrical pulse enters a transmission line structure with single pass transit time equal to ½ the duration of the pulse, open circuit at the extreme end and a switch at its center. After a delay equal to ¾ of the rectangular pulse duration the central switch is closed to couple the contents of the transmission line structure into another transmission line of half impedance. The output pulse maintains the initial voltage, but is of half the initial duration, and double the initial power.

A laser apparatus may include a master oscillator, a plurality of amplifiers, a photodetector device configured to detect a light beam traveling back along a laser beam path, and a controller. The photodetector device may include a first photodetector configured to detect energy of a light beam traveling back along the laser beam path and a second photodetector configured to detect power of the light beam traveling back along the laser beam path. The controller may be configured to determine that a return beam is generated when the intensity of the energy detection signal exceeds a first threshold. The controller may be configured to determine that a self-oscillation beam is generated when the intensity of the power detection signal exceeds a second threshold.

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 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.

A dielectric electrode assembly, and a method of manufacture thereof, including: a dielectric tube having a cylindrical cross-section and a relative dielectric constant, ε.sub.2, the dielectric tube filled with a gas having a relative dielectric constant, ε.sub.1; a structural dielectric having a relative dielectric constant, ε.sub.3 surrounding the dielectric tube; metal electrodes on opposite sides of the structural dielectric, the metal electrodes having a flat cross-sectional geometry; and the structural dielectric made from a material selected such that the relative dielectric constants of the structural dielectric, the dielectric tube, and the gas are interrelated and a uniform electric field is generated within the dielectric tube when power is applied to the metal electrodes.

Apparatus for and method of controlling a laser system capable of generating bursts of pulses of laser radiation having multiple alternate wavelengths in which an element controlling the wavelength is pre-positioned between bursts to be between its position for generating one wavelength and its position for generating another wavelength. Also disclosed is a system that determines an optimal control waveform for the element to move between positions using quadratic programming, dynamic programing, inversion feed forward control, or iterative learning control. A data storage device such as a pre-populated lookup table or a field programmable gate array may be used to store at least one optimal control parameter for each of a plurality of repetition rates.

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; a second window portion which hermetically seals the second opening; and a first electrode and a second electrode. 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.