Problem: to suppress the number of times complete gas replacement in a laser chamber. Solution: this excimer laser apparatus may include a gas supply unit, connected to a first receptacle that holds a first laser gas containing halogen gas and a second receptacle that holds a second laser gas having a lower halogen gas concentration than the first laser gas, that supplies the first laser gas and the second laser gas to the interior of the laser chamber. Then, gas pressure control in which the gas supply unit supplies the second laser gas to the interior of the laser chamber or a gas exhaust unit partially exhausts gas from within the laser chamber, and partial gas replacement control in which the gas supply unit supplies the first laser gas and the second laser gas to the interior of the laser chamber and the gas exhaust unit partially exhausts gas from within the laser chamber sequentially, may be selectively performed.

A beam reverser module for an optical power amplifier of a laser arrangement comprises at least one reflecting surface for receiving an incoming laser beam propagating in a first direction and reflecting the incoming laser beam into a second direction different from the first direction, wherein the at least one reflecting surface is a highly reflecting surface of at least one mirror.

In an inertial containment fusion (ICF) system which uses a KrF laser, it is beneficial to perform pulse compression of the laser output to produce a higher-power, higher-intensity laser pulse at the target. Such pulse compression involves counter-propagating laser pump and seed beams. A short-pulse seed beam is amplified as energy is extracted from a long-pulse pump beam. Because such energy extraction is invariably incomplete, a fraction of the pump energy will exit the compression cell in the same direction as the optics used to create the seed beam. The invention involves a gas consisting of a noble gas such as neon or argon which may be excited by an electron beam to enhance absorption. By proper choice of gas, cell length, electron-beam excitation, and time delay, the residual pump beam may be absorbed almost entirely with less than 0.01% transmitted laser energy through the invention.

Methods and systems for sterilizing a tools and equipment are disclosed, including using a UV source to generate a pulsed UV light within or exterior to an enclosure having a highly reflecting diffuse inner coated surface; and absorbing the pulsed light to sterilize. Other embodiments are described and claimed.

Methods and systems for sterilizing a room are disclosed, including using a laser to generate a pulsed laser beam; using a robotic arm to direct the pulsed laser beam to a scattering optical element and to change the position of the scattering optical element; and using the scattering optical element to substantially isotropically scatter the radiation of the pulsed laser beam to sterilize the room. The scattering optical element comprises a hollow fused silica bulb filled with solid fused silica spheres or a fiber optic bundle and in some embodiments the scattering optical element is rotated. The pulsed laser beam comprises a wavelength ranging between about 200 nm to about 320 nm and in some embodiments comprises nanosecond or picosecond light pulses. Other embodiments are described and claimed.

A narrow band laser apparatus may include: a laser resonator; a pair of discharge electrodes; a power supply; a first wavelength measurement device configured to output a first measurement result; a second wavelength measurement device configured to output a second measurement result; and a control unit. The control unit calibrates the first measurement result, based on a difference between the second measurement result derived when the control unit controls the power supply to apply a pulsed voltage to the pair of discharge electrodes with a first repetition frequency and the second measurement result derived when the control unit controls the power supply to apply the pulsed voltage to the pair of discharge electrodes with a second repetition frequency, the second repetition frequency being higher than the first repetition frequency.

Online calibration of laser performance as a function of the repetition rate at which the laser is operated is disclosed. The calibration can be periodic and carried out during a scheduled during a non-exposure period. Various criteria can be used to automatically select the repetition rates that result in reliable in-spec performance. The reliable values of repetition rates are then made available to the scanner as allowed values and the laser/scanner system is then permitted to use those allowed repetition rates.

A high voltage pulse generation device includes n transformer cores configuring a transformer, n being a natural number of 2 or more, each of the n transformer cores being configured to form a magnetic circuit along a first plane and to have a width in a first direction parallel to the first plane larger than a width in a second direction parallel to the first plane and perpendicular to the first direction; n primary electric circuits of the transformer connected in parallel to each other, each of the n primary electric circuits including at least one primary coil, and m pulse generation units connected in parallel to the at least one primary coil, m being a natural number equal to or more than 2; and a secondary electric circuit of the transformer including a secondary coil and connected to a pair of discharge electrodes.

A system and method for automatically performing gas optimization after a refill in the chambers of a two chamber gas discharge laser is disclosed. The laser is fired at low power, and the gas in the amplifier laser chamber bled if necessary until the discharge voltage meets or exceeds a minimum value without dropping the pressure below a minimum value. The power output is increased to a burst pattern that approximates the expected operation of the laser, and the amplifier chamber gas bled again if necessary until the voltage and an output energy meet or exceed minimum values, or until the pressure is less than a minimum value. The gas in the master oscillator chamber is then bled if necessary until the output energy of the master oscillator meets or falls below a maximum value, again without dropping the pressure in the chamber below the minimum value. While the pressure is adjusted, bandwidth is also measured and adjusted to stay within a desired range. Once the target values are provided, the process runs quickly without manual interaction.

A gas discharge light source includes a gas discharge system that includes one or more gas discharge chambers. Each of the gas discharge chambers in the gas discharge system is filled with a respective gas mixture. For each gas discharge chamber, a pulsed energy is supplied to the respective gas mixture by activating its associated energy source to thereby produce a pulsed amplified light beam from the gas discharge chamber. One or more properties of the gas discharge system are determined. A gas maintenance scheme is selected from among a plurality of possible schemes based on the determined one or more properties of the gas discharge system. The selected gas maintenance scheme is applied to the gas discharge system. A gas maintenance scheme includes one or more parameters related to adding one or more supplemental gas mixtures to the gas discharge chambers of the gas discharge system.