High energy laser beam replica producing method and system

摘要

An attenuated fiducial replica of the far field pattern of a high energy laser beam (15) is obtained by a system and method wherein a first fraction of an incident high energy beam is deflected from one reflective surface (13) of a holey plate (12) and the diffracted orders of the beam are transmitted from the holes (16) to a concave reflector (20), which reflects diffracted orders toward an opposite reflective surface of the holey plate. A zinc selenide partially reflective member (25) is disposed on-axis between the rear reflective surface (28) and the concave surface (21) for re-reflecting successive fraction­al portions of the reflected beam a selected number of times to attenuate the beam converging upon a focal plane from an effective focal distance greater than the physical length of the optical system.