A spatially and spectrally distributed long-laser system. Spatially separated phase-conjugate mirrors (PCMs) define a long-laser resonator cavity. The PCMs define, respectively, a power transmitting unit (master), and a power receiving unit (slave), as well as providing a secure two-way communications link between the units. The long-laser is mode-locked, minimizing third-party interception and detection. A wavefront-reversal device, using a MEMS spatial phase modulator, integrated with a retroreflector array, provides a true phase-conjugate (time-reversed) replica of the beam at each end of the system, providing auto-alignment, diffraction-limited performance, compensation for static and dynamic phase and polarization distortions, minimizing the FOV and scattering. The retroreflecting array initiates the oscillation mode. The SPM adaptive optical system bootstraps the retro-array by forming a simultaneous closed-loop system. The PCM emulates a deformable mirror with an integrated cat's eye retro-array, on a pixel-by-pixel basis, equivalent to a true wave-front reversal device at each end of the system.

Laser annealing apparatus includes a plurality of frequency-tripled solid-state lasers, each delivering an output beam of radiation at a wavelength between 340 nm and 360 nm. Each output beam has a beam-quality factor (M.sup.2) greater of than 50 in one transverse axis and greater than 20 in another transverse axis. The output beams are combined and formed into a line-beam that is projected on a substrate being annealed. Each output beam contributes to the length of the line-beam.

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.

An optical device has a first photonic waveguide provided on a substrate, a second photonic waveguide provided on the substrate and extending side by side with the first photonic waveguide, and a looped waveguide continuously connecting the first photonic waveguide and the second photonic waveguide on the substrate, wherein a width of at least one of the first photonic waveguide or the second photonic waveguide varies continuously along an optical axis, between a first position located at a side opposite to the looped waveguide and a second position connected to the looped waveguide, and wherein cross sections of the first photonic waveguide and the second photonic waveguide are congruent at the second position, and are incongruent at the first position.

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.

A laser apparatus according to the present disclosure includes an excitation light source configured to output excitation light, a laser crystal disposed on an optical path of the excitation light, a first monitor device disposed on an optical path of transmitted excitation light after having transmitted through the laser crystal to monitor the transmitted excitation light, a temperature adjustment device configured to adjust a temperature of the excitation light source to a constant temperature based on a temperature command value, and a controller configured to change the temperature command value based on a result of monitoring by the first monitor device.

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 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 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.

An exposure system according to an aspect of the present disclosure includes a laser apparatus emitting a pulse laser beam, an illumination optical system guiding the pulse laser beam to a reticle, a reticle stage moving the reticle, and a processor controlling emission of the pulse laser beam and movement of the reticle. The exposure system performs scanning exposure of a semiconductor substrate by irradiating the reticle with the pulse laser beam. The reticle has first and second regions. The processor instructs the laser apparatus about, based on proximity effect characteristics corresponding to the first and second regions, a value of a control parameter of the pulse laser beam corresponding to each region so that the laser apparatus emits the pulse laser beam with which a difference of the proximity effect characteristic of each region from a reference proximity effect characteristic is in an allowable range.