A system configuration that significantly improves the laser damage threshold of multi-layer dielectric gratings for lasers applications includes three main sections: 1) a laser module, 2) a TM polarization module, and 3) a multi-layer dielectric grating optimized for high efficiency operation with transverse magnetic polarized laser light.

In various embodiments, one or more optical elements are utilized to alter the numerical aperture of a radiation beam received from an optical fiber in order to accommodate the properties of a downstream collimator within a laser delivery head.

The invention relates to devices and methods of characterising a single unknown pulse signal. They create multiple replica of the original that may be more reliably measured, by dividing the signal through nodes and using different signal pathways that may apply a temporal delay. The device and methods have multiple fields of application, most notably with the internal confinement fusion industry.

An optical apparatus for spectrally shaping a laser beam within a fiber MOPA laser is disclosed. The apparatus includes a birefringent optic and a linear polarizer. The laser beam is divided between two orthogonal polarization axes of the birefringent optic having polarization mode dispersion. Propagation of the laser beam through the birefringent optic causes a wavelength-dependent phase shift between components of the laser beam in the two polarization axes. A polarizing direction of the polarizer is oriented between the two polarization axes. Propagation of the polarization-dispersed laser beam through the polarizer modulates the power spectral density of a transmitted portion of the laser beam. This spectral modulation can be tuned to shape a Gaussian spectral distribution from the master oscillator into a uniform spectral distribution for amplification by the power amplifier. The uniform spectrally-shaped laser beam can be amplified to higher powers than the original Gaussian laser beam.

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.

An additive manufacturing system may include an irradiation device configured to emit an energy beam having a manufacturing power level selected to additively manufacturing a three-dimensional object by irradiating a powder material, and a controller configured to perform one or more beam alignment operations when irradiating the powder material. The irradiation device may include a beam source, one or more beam positioning elements, a beam splitter configured to split a measurement beam from the energy beam, and one or more beam sensors configured to determine one or more parameters of the measurement beam. The one or more beam alignment operations may include determining position information of the energy beam based on the one or more parameters of the measurement beam, and aligning the energy beam with an optical axis of the irradiation device by adjusting a position of the one or more beam positioning elements based on the position information.

A system for determining an absolute carrier-envelope phase (CEP) of ultrashort laser pulses includes a laser system for generating a laser beam including ultrashort optical pulses of a duration of less than 10 fs, an ultrabroadband quarter-wave plate configured to polarize the laser beam, and a gas jet emitting a continuous jet stream into the laser beam. The system includes focusing optics to adjust a focal spot of the laser beam to the gas jet, and a detector arrangement including a beam block and a microchannel plate (MCP) imaging detector, wherein the laser beam is directed to the detector arrangement. The method involves using angular streaking to determine the absolute CEP of both elliptically and linearly polarized light.

The method comprises A method includes steps for creating at least two replicas of an input pulse to be characterised, varying the relative amplitude of the two replicas within a range, creating a nonlinear signal at each case of said amplitude variation, measuring the spectra of the nonlinear signals and recovering the spectral amplitude and phase of the input pulse with a proper algorithm. The system includes a replicator for creating at least two replicas of the input pulse and varying their relative amplitude within a range of relative amplitudes, a nonlinear medium, which obtains a nonlinear signal for each relative amplitude, and an analyzer, associated to the nonlinear signal for measuring and characterising spectrally each nonlinear signal.

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.

Provided is a two-photon spectroscopy including a light source configured to generate first laser light having a pulse, a pulse width correction device configured to receive the first laser light to output a second laser light, an optical system through which the second laser light passes, a first two-photon sensor configured to measure a first pulse width of the first laser light generated from the light source, and a second two-photon sensor configured to measure a second pulse width of the second laser light passing through the optical system, wherein the pulse width correction device corrects a difference between the first pulse width and the second pulse width.