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A laser beam profiler captures, displays, and records the spatial intensity profile of a laser beam at a particular plane transverse to the beam propagation path. Since there are many types of lasers— ultraviolet , visible , infrared , continuous wave , pulsed, high-power, low-power—there is an assortment of instrumentation for measuring ...
By observing and recording the beam pattern, for example, one can infer the spatial mode properties of the beam and whether or not the beam is being clipped by an obstruction; By focusing the laser beam with a lens and measuring the minimum spot size, the number of times diffraction limit or focusing quality can be computed.
In optics, a tophat beam (also Flat-top [1] or top-hat beam) such as a laser beam or electron beam has a near-uniform fluence (energy density) within a circular disk. It is typically formed by refractive [ 2 ] or diffractive optical elements from a Gaussian beam .
The equations below assume a beam with a circular cross-section at all values of z; this can be seen by noting that a single transverse dimension, r, appears.Beams with elliptical cross-sections, or with waists at different positions in z for the two transverse dimensions (astigmatic beams) can also be described as Gaussian beams, but with distinct values of w 0 and of the z = 0 location for ...
The diameter of the multimode beam is then M times that of the embedded Gaussian beam everywhere, and the divergence is M times greater, but the wavefront curvature is the same. The multimode beam has M 2 times the beam area but 1/M 2 less beam intensity than the embedded beam. This holds true for any given optical system, and thus the minimum ...
When measuring the beam parameter product and M 2, one uses the D4σ or "second moment" width of the beam to determine both the radius of the beam's waist and the divergence in the far field. [ 2 ] The BPP can be easily measured by placing an array detector or scanning-slit profiler at multiple positions within the beam after focusing it with a ...
A circular laser beam with uniform intensity across the circle (a flat-top beam) focused by a lens will form an Airy disk pattern at the focus. The size of the Airy disk determines the laser intensity at the focus.
The q-plate with topological charge q can generate a charge vortex based on the input beam polarization. An s-plate is a similar technology to a q-plate, using a high-intensity UV laser to permanently etch a birefringent pattern into silica glass with an azimuthal variation in the fast axis with topological charge of s. Unlike a q-plate, which ...