A reflective field-mapping beam shaper for creating a Gaussian intensity distribution from a uniform intensity high-energy laser beam

Abstract

The use of a "Field Mapping" beam shaping technique for generating near field Gaussian intensity patterns from uniform intensity ("flat top") laser beams is described. The design objective was to simulate realistic High Energy Laser (HEL) far field intensity patterns for laser effects testing purposes, without having to propagate the large distances necessary to obtain the true far field intensity profile and beam size typical of realistic target engagement scenarios.The field mapping approach presented uses a continuous surface mirror with a figure designed to redistribute the energy into a Gaussian distribution at the target plane. The use of a reflective system was desired to minimize cost and maximize wavelength diversity and laser damage threshold capability. Physical optics analyses are presented to illustrate the performance characteristics of a totally passive reflective field mapping beam shaper.