Optical field flattening devices

TLDR: In this paper, a light-polarizing beam splitter is employed for splitting the incident light beam into a transmitted first beam and a reflected second beam, which first and second beams are linearly polarized in mutually perpendicular respective directions.

Abstract: An optical device, for imposing a preselected degree of curvature upon an optical field associated with an image-bearing incident light beam, employs a light-polarizing beam splitter for splitting the incident light beam into a transmitted first beam and a reflected second beam, which first and second beams are linearly polarized in mutually perpendicular respective directions. Respective concave mirrors reflect the first and second beams so as to return them to the beam splitter, but respective polarization-changing members, mounted between the beam splitter and the concave mirrors, rotate the directions of linear polarization of the first and the second beams through 90* in the course of their passage from and back to the beam splitter. As a result, the returned first beam is reflected by the beam splitter, and the returned second beam is transmitted thereby for recombination with the first beam to form a single output beam.