1 School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121, China; 2 School of Physics and Electronic Information, Yanan Univeristiy, Yanan 716000, China
Abstract Based on the generalized truncated second-order moments, an approximate analytical formula of the beam propagation factor M2 of high-power laser beams passing through the optical system with multiple hard-edged apertures is deduced. Numerical examples of the beams passing through an aperture-spatial filter are enclosed, and the influences of amplitude modulations (AMs) and phase fluctuations (PFs) on the beam propagation quality of high-power laser beams passing through the multi-apertured ABCD optical system are considered and discussed. It is shown that PFs are able to degrade the beam propagation quality of laser beams more than AMs when the high-power laser beams passing through the aperture-spatial filter, furthermore, one or two aperture-lens optical systems configured appropriate aperture parameters are both able to upgrade the beam propagation quality of high-power laser beams. The M2 factor of Gaussian beam passing through the multi-aperture optical system is a special case in this paper.
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