Identification of the laser beam fi eld in the emission plane and in the measurement plane

The article considers an important practical problem that allows expanding the information on the laser beam parameters required for manufacturing and certification of laser sources. The only existing standardized numerical characteristic, the М 2 measure (GOST R ISO 11146-1-2008 “Lasers and laser installations (systems). Methods for measuring widths, divergence angles and propagation coefficients of laser beams”), which determines the quality of a laser beam, allows estimating the degree of similarity of the measured spatial distribution of the beam intensity only with the spatial distribution of the Gaussian intensity in the measurement plane. An alternative measure of similarity of the measured spatial distribution of the laser beam amplitude with a uniform distribution in the emitter plane or a spatial distribution of intensity with an arbitrary distribution in the measurement plane has been developed. It has been shown that the alternative measure of similarity when located in the emitter plane coincides with the aberration factor determining the source with the greatest axial luminous intensity. The proposed measure is universal and has a wider application than the М 2 measure, since it is associated with the characteristic of the field distribution homogeneity, the generalized area and the generalized diameter of the laser beam, which is an alternative to the beam diameter determined by GOST R ISO 11146-1-2008.

laser metrology, identification of intensity distributions, Gaussian distribution, laser beam, generalized beam area, generalized beam diameter, beam homogeneity, aberration factor