Patent ID: 8593734
Filing Date: 2013-11-26
Classification: G02B,G03H

Abstract:
1. An apparatus, comprising: a substrate made of an optical material having a first surface and a second surface; and a single three-dimensional diffractive element having a constant period, comprising a plurality of pixels disposed on the substrate, said three-dimensional diffractive element comprising: at least one area configured to receive an input optical beam; at least one further area configured to provide at least one output optical beam with an exit pupil expanded in one or two dimensions; wherein at least part of the input optical beam is diffracted in said at least one area to provide at least one optical beam substantially within the first and second surfaces and at least part of the at least one optical beam is further coupled out of the first or the second surface of the substrate by diffraction in said at least one further area to provide said at least one output optical beam; and wherein the at least one area and the at least one further area are configured such that the single diffractive element expands the at least one optical beam in at least two dimensions and simultaneously out-couples the at least one output optical beam.