A light source apparatus includes a gas discharge stage, a sensing apparatus, an optical arrangement, an adjustment apparatus, and a control apparatus. The gas discharge stage includes an optical amplifier including a chamber configured to hold a gas discharge medium outputting a light beam, and a set of optical elements configured to form an optical resonator around the optical amplifier. The optical arrangement is configured to image light from a plurality of distinct object planes within the gas discharge stage onto the sensing apparatus. The adjustment apparatus is in physical communication with one or more optical components within the gas discharge stage and is configured to modify at least one geometric aspect of the optical components. The control apparatus is communication with the sensing apparatus and the adjustment apparatus and is configured to provide a signal to the adjustment apparatus based on an output from the sensing apparatus.

A laser apparatus that can generate a high-quality laser beam is provided. The laser apparatus is provided with a laser medium and an insulation layer. The laser medium has a first surface and a second surface. Incident laser light is incident on the first surface. The second surface totally reflects the incident laser light that is incident to the second surface at an incident angle equal to or larger than a critical angle. The insulation layer covers a second area of the second surface that surrounds a first area of the second surface, the first area totally reflecting the incident laser light. The laser medium is exposed in the first area.

An extended optical pulse stretcher is provided that combines confocal pulse stretchers in combination to produce, for example, 4 reflections, 4 reflections, 12 reflections, and 12 reflections per optical circuit configuration. The inclusion of the combination of different mirror separations and delay path lengths can result in very long pulse stretching, long optical delays, and minimal efficiency losses. Also, in the extended optical pulse stretcher, at least a beam splitter can be positioned relative to the center of curvature of the mirrors to “flatten” each of the circuits to enable the beam to propagate in the same plane (e.g., parallel to the floor). Also, the curvatures and sizes of the individual mirrors can be designed to position the beam splitter closer to one of the banks of mirrors to allow the optical pulse stretchers to properly fit in an allocated location in a laser system.

A laser apparatus according to an aspect of the present disclosure includes a master oscillator configured to emit a laser beam, an amplifier including an optical resonator and configured to amplify the laser beam emitted by the master oscillator in the optical resonator, and a phase shift structure disposed on an optical path between the master oscillator and the amplifier at a position closer to the amplifier than a middle point of the optical path. The phase shift structure includes a plurality of cells having different phase shift amounts for the laser beam. The cells have a disposition interval of 80 μm to 275 μm inclusive.

A laser device according to one embodiment includes a laser light source configured to output pulsed laser light L1 and a pulse width control unit configured to amplify the pulsed laser light output from the laser light source, change a pulse width of the pulsed laser light, and output the pulsed laser light. The pulse width control unit includes a first laser amplifier configured to amplify the pulsed laser light and a pulse waveform manipulation unit disposed between the first laser amplifier and the laser light source and configured to manipulate a pulse waveform of the pulsed laser light.

Systems, apparatuses, and methods are provided for dual-pass amplification of laser beams along a common beam path. An example method can include generating a first laser beam and a second laser beam. Subsequently, the example method can include performing dual-pass amplification of the first laser beam and the second laser beam along a common beam path. In some aspects, the first laser beam can include a first wavelength, the second laser beam can include a second wavelength different from the first wavelength.

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.

A laser system including: A. a laser apparatus configured to output a pulse laser beam; B. an optical pulse stretcher including a delay optical path for expanding a pulse width of the pulse laser beam; and C. a phase optical element included in the delay optical path and having a function of spatially and randomly shifting a phase of the pulse laser beam. The phase optical element includes a plurality of types of cells providing different amounts of phase shift to the pulse laser beam and arranged irregularly in any direction.

A laser system includes a beam shaping unit, a random phase plate, and a collimating optical system in an optical path between a solid-state laser device and an excimer amplifier. When a traveling direction of a laser beam entering the excimer amplifier is a Z direction, a discharge direction of a pair of discharge electrodes is a V direction, a direction orthogonal to the V and Z directions is an H direction, a shaping direction of the beam shaping unit corresponding to the V direction is a first direction, a shaping direction of the beam shaping unit corresponding to the H direction is a second direction, an expansion rate in the first direction is E1, and an expansion rate in the second direction is E2, the beam shaping unit expands a beam section of the laser beam such that an expansion ratio defined by E2/E1 is higher than 1.

A titanium-sapphire laser apparatus may include a continuous wave oscillation laser unit, an amplification oscillator, a pulsed laser unit, an error detector, an error controller, and an optical path length corrector. The amplification oscillator may include an optical resonator and a titanium-sapphire crystal that is provided in an optical path in the optical resonator. The error detector may be provided in an optical path of leak light of seed light from the optical resonator, and may detect an optical path length error between an optical path length in the optical resonator and a positive integer multiple of a wavelength of the seed light and output an optical path length error signal. The optical path length corrector may vary the optical path length in the optical resonator on a basis of a signal resulting from adding a correction value to the optical path error signal.