Investigations of multimode stimulated emission from powerful CO₂lasers

<title>About particularities of intensities distribution in a cross-section of powerful laser beams</title>

“…x '=z sin(qa)+x cos(qcx), z '=z cos(qcz)-x sm(qci), a=a/A Using for calculations of the characteristics of a field expression (2), and also the ray method used in it is possible to establish the basic features of transformation of initial amplitude -phase distribution. The calculations show, that even at small depth of a phase modulation in an initial section the diffraction effects result in significant spatial redistribution of intensity.…”

“…The amplitude of a field of such wave under longitudinal coordinate z=O is 'P(x, y) = exp{-(x2 + y2 ) /w + im / 2 sin(2nx / a)), (1) x 0 where m -is a parameter describing the depth of phase modulation, x,y -are cross coordinates, a -is period of modulation. At the distance z from the initial plane the field can be presented as a superposition of gaussian beams'°: 11 = qJq (m I 2)G(x' , y, z'), (2) where Jq -is the bessel function about q order, Gq('x ,Z915 a function, which describes a field of a gaussian beam",…”