diffraction optical waveguide device for expansion of the exit pupil.

摘要

diffraction optical waveguide device for expansion of the exit pupil. An optical device for expanding the light input in two dimensions in an augmented reality display is disclosed. The device comprises a waveguide (12) and three linear diffraction grids h0, h1, h2. an incident beam from a projector illuminates an input network h0 with polychromatic light, and the light is coupled to the waveguide (12). the other two networks h1, h2 overlap one another. The light may be diffracted by an H1 network in a first diffracted order and toward another H2 network which may couple the light out of the waveguide (12) towards the viewer. In another arrangement, the cross networks h1, h2 may be replaced by a photonic crystal (19) having a regular set of pillars (20) which create a number of effective diffraction grids.