Redistribution of the laser beam power using diffractive optical elements

The use of laser technologies in the production of optical fiber requires a careful choice of optical systems for positioning and transforming the laser beam. The purpose of this research is to determine a possibility of the redistribution of the laser beam power using diffractive optical elements. It was determined that for a radius of the focusable beam R-f = r(f) = 2.2x10(-2) m, the length of the focal spot will be increased to a value L = 13.6x10(-3) m, which is 1.2 times larger than R-f = r(f) = 1.8x10(-2) m. In this case, the intensity of the laser beam at the centre of the focal spot, q(0), and the maximum value, q(max), decreased by 1.1 times. An approximation of function q(x, y) by polynomials of degree n = 5 and m = 3 was performed. It is shown that the maximal relative error of approximation does not exceed 4%, and the relative error of approximation in the centre of the focal spot does not exceed 3%. Presented equations can be used to calculate the intensity distribution in the focal plane of diffractive optical elements.