FIELD: optical engineering.
SUBSTANCE: invention relates to the field of optical engineering and can be used to create the same conditions for high-precision processing of various materials based on the use of laser beams. Etching depth of 50 % of elementary cells in a substrate made on a crystalline material, whose surfaces are oriented parallel to the optical axis of this material, is determined from the ratio 
, where λ is the radiation wavelength of the plate application, n0 and ne – the refractive indices of the crystalline material for ordinary and extraordinary rays, respectively, the deviation in the depth of etching of the elementary cells should not exceed 5 % of the value of h.
EFFECT: expansion of the field of application of a random phase plate for leveling the intensity distribution in the cross section of laser beams with a degree of coherence, a slightly lower degree of coherence of single-mode Gaussian beams with beam quality M2≤1.1, which corresponds to the beam quality corresponding to the values of M2≥2.
1 cl, 4 dwg
