ISO 11146-2 PDF
ISO , Optics and optical instruments — Lasers and laser-related equipment — Vocabulary and symbols; ISO , Lasers and laser-related equipment. ISO. First edition. Lasers and laser-related equipment —. Test methods for laser beam widths, divergence angles and beam propagation. ISO/TR. First edition. Lasers and laser-related equipment — .. in ISO and ISO are essentially based on (but not.
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Most CCD beam profiler’s software can compute the knife-edge width numerically.
Retrieved July 2, The measured curve is the integral of the marginal distribution, and starts at the total beam power and decreases monotonically to zero power. To overcome this drawback, an innovative technology offered commercially allows multiple directions beam scanning to create an image like beam representation. The definition given before holds for stigmatic circular symmetric beams only.
The baseline is easily measured by recording the average value for each pixel when the sensor is not illuminated. The beam width can be measured in units of length at a particular plane perpendicular to the beam axis, but it can also refer to the angular width, which is the angle subtended by the beam at the source. Retrieved June 3, For astigmatic beams, however, a more rigorous definition of the beam width has to be used:. The beam diameter or beam width of an electromagnetic beam is the diameter along any specified line that is perpendicular to the beam axis and intersects it.
The angular width is also called the beam divergence. The profile is then measured from the knife-edge velocity and its relation to the detector’s energy reading. The angle between the maximum peak of radiated power and the first null no power radiated izo this direction is called the Rayleigh beamwidth. This is also called the half-power beam width HPBW.
Beam diameter – Wikipedia
Views Read Edit View history. From Wikipedia, the free encyclopedia. A beam may, for example, have an elliptical cross section, in which case the orientation of the beam diameter must be specified, for example with respect to the 11146-2 or minor axis of the elliptical cross section. By using tomographic reconstruction, mathematical processes reconstruct the laser beam size in different orientations to an image similar to the one produced by CCD cameras. This is the beam diameter definition that is used for computing the maximum permissible exposure to a laser beam.
Beam diameter usually refers to a beam of circular cross section, but not necessarily so. The width of laser beams 1146-2 be measured by capturing an image on a cameraor by using a laser beam profiler.
Archived from the original pdf on June 4, International standard ISO The main advantage of this scanning method is that it is free from pixel size limitations as in CCD cameras and allows beam reconstructions with wavelengths not usable with existing CCD technology. The solution for D86 is found by ixo the area of increasingly larger circles around the centroid until the area contains 0.
If the beam does not fill more than a third of the beam profiler’s sensor area, then there will be a significant number of pixels at the edges of the sensor that register a small baseline value the background value. The term “beam width” may be preferred in applications where the beam does not have circular symmetry.
Portable Document Format (PDF)
The American National Standard Z Before the advent of the CCD beam profiler, the beam width was 11146–2 using the knife-edge technique: Radiant Zemax Knowledge Base. Stigmatic and simple astigmatic beams. Five definitions of the beam width are in common use: Since beams typically do not have sharp edges, the diameter can be defined in many different ways.
This page was last edited on 18 Decemberat For cases related to radio antennas, see beamwidth.
МКС EN ISO 11146-2:2009
Full width at half maximum. Intrinsic and geometrical laser beam classification, propagation and details of test methods. Intrinsic and geometrical laser beam classification, propagation and details of test methods”. Unlike the previous beam width definitions, the D86 width is not derived from marginal distributions. Retrieved from ” https: The simplest way to define the width of a beam is to choose two diametrically opposite points at which the irradiance is a specified fraction of the beam’s peak irradiance, and take the distance between them as a measure of the beam’s width.
The main drawback of the knife-edge technique is that the measured value is displayed only on the scanning direction, minimizing the amount of relevant beam information.
For example, applications of high-energy laser weapons and lidars require precise knowledge of how much transmitted power actually illuminates the target. Unlike other systems, a unique scanning technique uses several different oriented knife-edges to sweep across the beam.