Distributed zero-order component in a holographic projector

Abstract

A zero-order suppression device for a holographic wavefront includes a first 630 and second 640 microlens array (MLA) and a spatial filter 650. Each first microlens of the first microlens array is coupled to a corresponding second microlens of the second microlens array to form an array of microlens pairs. The spatial filter is between the first and second microlens arrays and includes an array of light suppression elements 651, each aligned with a corresponding microlens pair. The spatial filter may be on a back focal plane of the first microlens array. Each light suppression element may be mainly aligned with a focal point formed by the first microlens array when receiving the, or a portion of the, holographic wavefront. Each light suppression element may have a size mainly equal to that of the focal point and include light absorbing material. Each light suppression element may include a hole in a reflective component turning the optical path between the first and second microlens arrays. The spatial filter may be on the front focal plane of the second microlens array. There may be a louvre array 800 between the microlens arrays with louvres 801 perpendicular to the microlens arrays.

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