3D display based on complete digital optical phase conjugation

Digital optical wavefront reconstruction for 3D display at tens or hundreds centimeters scale with viewing angle over 100° calls for resolutions at sub-wavelength scale. However the pixel pitches of spatial light modulators (SLM) are at micrometer or tens of micrometer scale. When people generated 3D images by digital holography using SLMs they had to make the interference patterns very sparse, resulting in small image size or narrow viewing angle. The paper employed an adiabatic waveguide taper made of quantities of single-mode waveguides to decompose complicated light fields into simpler forms so that complete digital optical phase conjugation (CDOPC) could be performed using low resolution SLMs. Then the paper introduced an optical transforming unit to project the reconstructed small wavefronts over a large volume while maintaining large viewing angle. The paper shows both theoretically and experimentally that 3D display systems based on CDOPC could create large size 3D images with large viewing angle and diffraction limited image quality. Besides, CDOPC might also be widely used for 3D measurement, optical tweezers, high energy laser beam forming, etc.