Near field beam shaping optics, also called beam transformers, remap an input Gaussian profile to a top-hat profile. The top-hat profile is created at some working distance away from the shaping element where a corrector element is placed to "flatten" the phase of the top-hat profile to allow it to propagate some finite distance as a "collimated" beam. Creating a top-hat profile requires the surface of the shaping element to be highly aberrated resulting in designs that are typically either a diffractive surface or an aspheric surface each composed of many higher-order aspheric coefficients. Diffractives and higher-order refractive designs offer several challenges and limitations in manufacturing. The design space of using all spherical elements or even a combination of aspheric and spherical elements has not been completely explored to see if there are any advantages of reducing the manufacturing tolerances or limitations for beam shaping systems. This paper will explore the comparison of the number of elements required for diffractive, aspheric, and spherical designs to meet the same beam shaping requirement and provide details related to the manufacturability of each type of design.

Date Published: 12 September 2008
PDF: 7 pages
Proc. SPIE 7062, Laser Beam Shaping IX, 70620L (12 September 2008);

Published in SPIE Proceedings Vol. 7062:
Laser Beam Shaping IX
Andrew Forbes; Todd E. Lizotte, Editor(s)