Provided is an apparatus for measuring a light beam profile, comprising three rotary disks fixed on three positions of a rotary shaft connected to a motor at regular intervals, respectively while shifted by 120 degrees each other in a rotational direction, each rotary disk having three deformed holes with knife edges and six deformed holes defining light-passing openings and a photodetector arranged outside a set of the three rotary disks in a transmission direction of the light beam to receive the light beam passing through the three rotary disks.

Provided herein are a system and a method thereof which allows for calibrating a laser or getting characteristics of the laser by measuring the temporally and spatially resolved beam profile and power density cross-section using non-contact radiometry. An example method includes receiving a radiation beam from a light source by protrusions that protrude from a plate. The example method further includes imaging the protrusions, measuring a respective temperature of each of the protrusions based on the imaging, and profiling the radiation beam based on the measuring.

A light beam measurement device includes: a polarization measurement unit including a first measurement beam splitter provided on an optical path of a laser beam and configured to measure a polarization state of the laser beam having been partially reflected by the first measurement beam splitter; a beam profile measurement unit including a second measurement beam splitter provided on the optical path of the laser beam and configured to measure a beam profile of the laser beam having been partially reflected by the second measurement beam splitter; and a laser beam-directional stability measurement unit configured to measure a stability in a traveling direction of the laser beam, while the first measurement beam splitter and the second measurement beam splitter are made of a material containing CaF.sub.2.

A method and a device for measuring light field distribution are provided; including steps of utilizing the optical trap to stably levitating particles, moving the optical trap to bring the particles close to the light field to be measured, and utilizing the photodetector to collect the scattered light signals of the particles at different positions in the three-dimensional space of the light field to be measured, and calculating the light field distribution of the light field to be measured according to the scattered light intensity which is proportional to the light intensity at that position. The device for measuring the optical field distribution includes a laser, an optical trapping path, particles, a photodetector, a control system and an upper computer; the laser emits a laser, passes through the optical trapping path, and emits highly focused captured light B to form an V optical trap to capture particles.

A device for determining a focal position of a laser beam, in particular a processing laser beam in a laser processing head, has an optical decoupling element for decoupling a partial beam from a beam path of the laser beam, a detector for detecting at least one beam parameter of the partial beam, and at least one optical element with an adjustable focal length, which is arranged in a region of the beam path of the partial beam between the optical decoupling element and the detector. Also disclosed is a laser processing head which includes a device of this type, as well as a method for determining a focal position of a laser beam.

Methods and apparatus for determining an intensity profile of a radiation beam. The method comprises providing a diffraction structure, causing a relative movement of the diffraction structure relative to the radiation beam from a first position, wherein the radiation beam does not irradiate the diffraction structure to a second position, wherein the radiation beam irradiates the diffraction structure, measuring, with a radiation detector, diffracted radiation signals produced from a diffraction of the radiation beam by the diffraction structure as the diffraction structure transitions from the first position to the second position or vice versa, and determining an intensity profile of the radiation beam based on the measured diffracted radiation signals.

A laser radiation system according to a viewpoint of the present disclosure includes a first optical system configured to convert a first laser flux into a second laser flux, a multimirror device including mirrors, configured to be capable of controlling the angle of the attitude of each of the mirrors, and configured to divide the second laser flux into laser fluxes and reflect the laser fluxes in directions to produce the divided laser fluxes, a Fourier transform optical system configured to focus the divided laser fluxes, and a control section configured to control the angle of the attitude of each of the mirrors in such a way that the Fourier transform optical system superimposes the laser fluxes, which are divided by the mirrors separate from each other by at least a spatial coherence length of the second laser flux, on one another.

A method assesses the beam profile of a light beam of a non-contact tool setting apparatus, the apparatus including a transmitter for emitting the light beam and a receiver for receiving the light beam. The receiver generates a beam intensity signal describing the intensity of received light. The apparatus is mounted to a machine tool having a spindle that is moveable relative to the non-contact tool setting apparatus. The method includes loading an object having an edge into the spindle of the machine tool and using the machine tool to move the spindle relative to the apparatus so that the edge of the object passes through the light beam. The beam profile of the light beam is then determined using the beam intensity signal generated at a plurality of positions during the step (ii) of moving the edge of the object through the light beam.

An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.

A to-be-measured partially coherent fractional vortex beam passes through a scattering object, an error between measurable information and to-be-measured information is minimized by using an optimization algorithm, and a main electric field mode and a weight of a to-be-measured fractional vortex beam are reconstructed by using a multimode stacked diffraction algorithm. A cross-spectral density function of the partially coherent fractional vortex beam is calculated, a cross-spectral density of a partially coherent fractional vortex optical field is reconstructed, and complete information including light intensity, a light intensity association, an electric field association, a phase, and the like of the partially coherent fractional vortex optical field is obtained. After the complete information of the partially coherent fractional vortex optical field is obtained, reverse transmission calculation is performed to obtain a source field vortex phase distribution, thereby implementing accurate topological charge measurement of the fractional vortex beam under low coherence conditions.