An embodiment of the present disclosure discloses a method for detecting flatness of a fluorescent wheel in a laser light source, comprising: acquiring, during the rotation of a fluorescent wheel, a spot of laser light emitted by a laser reflected from a substrate of the fluorescent wheel; determining an inner diameter of the spot; and determining flatness of the fluorescent wheel according to the inner diameter of the spot.

The line narrowed laser apparatus configured to perform a plurality of burst oscillations including a first burst oscillation and a second burst oscillation next to the first burst oscillation to output a pulse laser beam. The line narrowed laser apparatus comprises a laser resonator, a chamber provided in the laser resonator, a pair of electrodes provided in the chamber, an electric power source configured to apply a pulsed voltage to the pair of electrodes, a wavelength-selecting element provided in the laser resonator, a spectral width varying unit provided in the laser resonator, a wavelength variable unit configured to change a selected wavelength selected by the wavelength-selecting element, and a controller. The controller is configured to control the wavelength variable unit based on an amount of control of the spectral width varying unit in a period from a time of ending the first burst oscillation to a time of starting the second burst oscillation.

In a laser oscillator, a pair of electrodes is disposed in a housing into which a gas is sealed, a waveguide is formed by the pair of electrodes, and a laser beam is configured to be extracted from an end of the housing. The laser oscillator includes a mirror holder attached to an end of the electrode, the end serving as an end of the waveguide, and a reflection mirror attached to the mirror holder and reflecting a laser beam generated in the waveguide. In the laser oscillator, a passage through which a cooling medium is passed is formed inside each of the pair of electrodes.

In a laser oscillator, a pair of electrodes is disposed in a housing into which a gas is sealed, a waveguide is formed by the pair of electrodes, and a laser beam is configured to be extracted from an end of the housing. The laser oscillator includes a mirror holder attached to an end of the electrode, the end serving as an end of the waveguide, and a reflection mirror attached to the mirror holder and reflecting a laser beam generated in the waveguide. In the laser oscillator, a passage through which a cooling medium is passed is formed inside each of the pair of electrodes.

A laser machining device capable of recovering an exhaust performance of a dry pump easily is provided. A laser machining device includes: an oscillating portion that generates a machining laser beam G; an enclosure portion in which a first gas is enclosed; and an exhausting portion that exhausts the first gas together with a dirt generated in the enclosure portion in association with an operation of the oscillating portion. The exhausting portion includes: a dry pump; a first line that connects the enclosure portion and the dry pump; a second line that supplies a second gas having a higher pressure than the first gas to the dry pump; a valve portion that opens or closes the first line and the second line; and a control unit that controls opening or closing of the valve portion.

A laser machining device capable of recovering an exhaust performance of a dry pump easily is provided. A laser machining device includes: an oscillating portion that generates a machining laser beam G; an enclosure portion in which a first gas is enclosed; and an exhausting portion that exhausts the first gas together with a dirt generated in the enclosure portion in association with an operation of the oscillating portion. The exhausting portion includes: a dry pump; a first line that connects the enclosure portion and the dry pump; a second line that supplies a second gas having a higher pressure than the first gas to the dry pump; a valve portion that opens or closes the first line and the second line; and a control unit that controls opening or closing of the valve portion.

The present invention relates to a system for recirculating the gas atmosphere within an excimer laser system, where contaminates, created in the laser's operation, are removed, and the gas concentrations of additive gases, such as Xe, Kr, or others, depleted in the laser operation, are rebalanced to specific lasing mixtures by analyzation and component replenishment from one or more external supplies.

An example laser system includes a laser source to transmit a source light generated based on optical feedback provided by a laser cavity. The laser system further includes a beam-splitter to split the source light into a reference light and a split source light. The laser system further includes a modulator to modulate the split source light's frequency. The modulated light may be transmitted towards and reflected from a target. The modulator and beam-splitter may receive, frequency-modulate, and pass the reflected light to the laser cavity. The laser cavity amplifies the reflected light and transmits the amplified light toward the beam-splitter, such that the amplified light follows a same path as the reference light. The laser system further includes a detector to receive the reference light and amplified light, and detect a beating frequency as an indication of presence of the reflected light. Related methods and devices are also disclosed.

Methods and apparatus for in situ compensation for damage or misalignment of optical elements are disclosed. Also disclosed are methods and apparatus for facilitating alignment of replacement optical elements so that the amount of time in a system including the optical elements can be reduced. Also disclosed are methods and apparatus for processing an image of a beam generated by an optical system to extract information indicative of an extent of damage to optical elements in the optical system and/or misalignment of the optical elements. Information pertaining to an extent of damage to optical elements in the optical system can be used to optimally schedule maintenance events for the optical system.

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.