System and method for high-quality speckle-free phase-only computer-generated holographic image projection

A holographic image-display system comprising:

• a spatial light modulator to phase modulate light from at least one light source configured to illuminate the spatial light modulator;
• a processing unit configured to divide an image plane into a plurality of image blocks and form a separate phase function having two-dimensional polynomial terms for each block, wherein a target image is mapped on the spatial light modulator aperture in a geometrically distorted form such that the energy distribution of the initial computer-generated hologram on a plane of the spatial light modulator is substantially uniform,
• wherein the processing unit is further configured to multiply the image blocks by the phase function to obtain an image plane wavefield which, with backpropagation, generates an initial computer-generated hologram with a substantially uniform energy distribution, to constitute the source of a phase hologram to be written on the spatial light modulator,
• wherein the processing unit is further configured to compute the phase hologram to be written on the spatial light modulator followed by discarding magnitude information to obtain pure phase,
• wherein the processing unit is further configured to map each image block of the image plane on a particular spatial light modulator region on the plane of the spatial light modulator using the separate phase function, and
• wherein the area of each of the spatial light modulator regions is proportional to the energy content of the corresponding image block of the image plane.