A laser apparatus includes a chamber accommodating a pair of discharge electrodes, a gas supply and exhaust device configured to supply laser gas to an interior of the chamber and exhaust laser gas from the interior of the chamber, and a controller. The controller performs first control to control the gas supply and exhaust device so as to suspend laser oscillation and replace laser gas in the chamber at every first number of pulses or first elapsed time, and second control to control the gas supply and exhaust device so as to suspend laser oscillation and replace laser gas in the chamber before the first control at every second number of pulses less than the first number of pulses or second elapsed time less than the first elapsed time.

An apparatus includes: a magnetic switching network configured to activate an excitation mechanism in a discharge chamber. The magnetic switching network includes: an initial energy storage node configured to receive electrical current from an electrical charger; an additional energy storage node; and at least one electrical element between the initial energy storage node and the additional energy storage node. The apparatus also includes an electronic network electrically connected to the additional energy storage node, the electronic network configured to control a voltage at the additional energy storage node.

An impedance matching circuit for a gas-laser excitation system includes a high-frequency connection line configured to be connected at a first connection point to a power source and at a second connection point to a gas-laser electrode. The impedance matching circuit is characterized in that an impedance of at least one section of the high-frequency connection line changes by a change to a configuration of the high-frequency connection line, in particular to at least one parameter of the high-frequency connection line in the at least one section.

A discharge excitation gas laser device includes: first and second discharge electrodes disposed to face each other; a plurality of peaking capacitors connected to the first discharge electrode; a charger; a plurality of pulse power modules, each one of the pulse power modules including a charging capacitor to which a charged voltage is applied from the charger, a pulse compression circuit that pulse-compresses and outputs electrical energy stored in the charging capacitor as an output pulse to a corresponding peaking capacitor, and a switch disposed between the charging capacitor and the pulse compression circuit; a plurality of output pulse sensors, each one of the output pulse sensors detecting an output pulse output by a corresponding pulse power module; and a control unit configured to control, based on a detection result of each of the output pulse sensor, a tinting of a switch signal to be input to a corresponding switch.

The laser system includes a first laser apparatus, a second laser apparatus, a charging voltage measuring unit configured to measure the charging voltage of the first storage capacitor and the charging voltage of the second storage capacitor, at least one bleeding circuit configured to reduce the charging voltage of the first storage capacitor and the charging voltage of the second storage capacitor, and a bleeding circuit controller configured to control the at least one bleeding circuit based on the voltage measured by the charging voltage measuring 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 apparatus may include: an optical amplifier configured to amplify a laser beam outputted from a master oscillator; an optical-amplifier power supply configured to supply an alternating current for optical amplification to the optical amplifier; and a laser controller. The optical-amplifier power supply may include: an alternating current generation circuit including an inverter circuit configured to change output amplitude in accordance with a duty cycle, the alternating current generation circuit being configured to generate the alternating current from an output of the inverter circuit; and a power supply control circuit configured to hold control information defining correspondence relations between command values from the laser controller and duty cycles of the inverter circuit, determine a duty cycle corresponding to a command value received from the laser controller based on the control information, and provide the determined duty cycle to the inverter circuit.

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 pulsed power circuit including one or more magnetic switches respectively implemented as one or more inductors having saturable cores wherein, after a discharge pulse, each saturable core is repeatably reset to an initial bias point on its magnetization curve by a reset pulse having variable characteristics determined, for example, by chamber operating conditions so that the saturable core is able to function reliably and consistently.

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.