A laser light source unit for vehicles is provided, having a resonator containing a first end mirror and a second end mirror and an active laser medium in between. The laser light source unit has a pump device for generating a pump radiation into the resonator. The pump radiation is configured such that laser light of the first wavelength, a second wavelength, and/or a third wavelength can be radiated. An intermediate mirror is configured so that the radiation of the second wavelength is reflected, and the radiation of the third wavelength is transmitted. A third end mirror is configured so that the radiation of the second wavelength is reflected. A color control module acts on the radiation of the second wavelength and/or the third wavelength so that an intensity of the stimulated emission of the radiation of the second wavelength is adjusted to the radiation of the third wavelength.

A compact laser system with a folded annular resonator cavity defined by spherical mirrors (17, 18), enabling the generation of a multipass beam path between the mirrors, each beam pass inclined at a small angle to the axis between the mirrors to form a zig-zag path (28, 29) therebetween. A long optical path is achieved within a short physical structure. The optical resonator cavity is confined in the gap between two cylindrical coaxial electrodes (13, 14) receiving RF power to excite the lasing gas. Apertures (23) are provided in the main cavity mirrors (17, 18), with a high reflectivity end mirror (24) behind one aperture at one end and a partially reflective output coupler (25) at the other end. A channeled ceramic cylindrical element (15, 20) within the annular shaped gap between the two cylindrical electrodes confines the lasing gas to the channels (16).

A laser apparatus includes at least one electro-optic (EO) medium through which a polarized laser beam passes for N times, forming a plurality of first-pass to Nth-pass beams, by reflecting the polarized laser beam from at least one reflection mirror, and a power supplier configured to alternately provide a 1/N of a half-wave (λ/2) or quarter-wave (λ/4) voltage and remove the voltage to the EO medium, λ being a wavelength of the polarized laser beam. The at least one EO medium is tilted at angle θ and/or angle di with respect to one of the plurality of first-pass to Nth-pass beams. The at least one EO medium comprises a M number of EO mediums, and the power supplier is configured to alternately provide a 1/M*N of a half-wave (λ/2) or quarter-wave (λ/4) voltage and remove the voltage to each of the M number of EO mediums.

Provided is a semiconductor laser element including: a resonator structure; and a first reflection film and a second reflection film provided on a non-emission end surface of the resonator structure and an emission end surface of the resonator structure, respectively. Reflectance R of the second reflection film at a gain wavelength satisfies the following relational expression: R1≤R≤R(Oc)×C where R1 is reflectance of the second reflection film when the resonator structure performs laser oscillation with power 1.4 times a minimum value of threshold power which is minimum power for the resonator structure to perform the laser oscillation, R(Oc) is reflectance of the external resonance mirror, and C is a ratio of light, which is reflected by the external resonance mirror and is incident in the resonator structure, to light which is reflected by the external resonance mirror.

An optical system for increasing contrast of pulsed laser radiation includes a first polarization setting optical unit for setting an elliptical polarization state of the pulsed laser radiation, and a multipass cell having at least two opposing mirrors. The pulsed laser radiation passes the multipass cell with formation of a plurality of intermediate focus zones. The multipass cell is filled with a gas having an optical nonlinearity that causes an intensity-dependent rotation of an alignment of the elliptical polarization state of the pulsed laser radiation, such that the multipass cell outputs beam portions having differently aligned elliptical polarization states on account of the intensity-dependent rotation. The optical system further includes an optical beam splitting system for splitting the beam portions having differently aligned elliptical polarization states.

A method includes driving, while producing a burst of pulses at a pulse repetition rate, a spectral feature adjuster among a set of discrete states at a frequency correlated with the pulse repetition rate; and in between the production of the bursts of pulses (while no pulses are being produced), driving the spectral feature adjuster according to a driving signal defined by a set of parameters. Each discrete state corresponds to a discrete value of a spectral feature. The method includes ensuring that the spectral feature adjuster is in one of the discrete states that corresponds to a discrete value of the spectral feature of the amplified light beam when a pulse in the next burst is produced by adjusting one or more of: an instruction to the lithography exposure apparatus, the driving signal to the spectral feature adjuster, and/or the instruction to the optical source.

A laser apparatus according to an aspect of the present disclosure includes a laser oscillator that outputs pulsed laser light, a deformable mirror including a deformer that deforms a reflective surface, a first processor that drives the deformer during the period for which the reflective surface reflects the pulsed laser light, a homogenizer that homogenizes the pulsed laser light reflected off the deformable mirror, and a spectrum measuring instrument that measures the spectrum of the pulsed laser light homogenized by the homogenizer.

A system includes: an optical source including a plurality of optical oscillators; a spectral analysis apparatus; and a controller. Each optical oscillator is configured to produce a light beam. The controller is configured to: determine, based on data from the spectral analysis apparatus, whether the spectral property of the light beam of one of the optical oscillators is different than the spectral property of the light beam of at least another of the plurality of optical oscillators. If the spectral property of the light beam of the first one of the optical oscillators is different than the spectral property of the light beam of another of the optical oscillators, the controller is configured to adjust the spectral property of the light beam of the first one of the optical oscillators or of the light beam of at least one other of the optical oscillators.

A laser device includes: a first reflecting unit; a second reflecting unit; a gain unit provided between the first reflecting unit and the second reflecting unit; a divider provided after the first reflecting unit and configured to divide laser light from the first reflecting unit into first light and second light; a first end portion positioned separately from the divider in a first direction, and positioned after the divider, the first end portion being configured to output, as output light, the first light or the first light that has been amplified; and a second end portion positioned separately from the divider in a second direction different from the first direction, the second end portion being configured to output the second light.

A line narrowing device includes first and second prisms disposed at positions different in a wavelength dispersion direction of any of the first and second prisms, a third prism disposed on the optical path of an optical beam and through which the beam width of the optical beam is enlarged and first and second parts of the optical beam are incident on the first and second prisms, respectively, a grating disposed across the optical path of the first part having passed through the first prism and the optical path of the second part having passed through the second prism, a first actuator configured to adjust the incident angle of the first part on the grating, a second actuator configured to adjust the incident angle of the second part on the grating, and a third actuator configured to adjust an energy ratio of the first and second parts.