COMPACT PROJECTION LIGHT ENGINE FOR A DIFFRACTIVE WAVEGUIDE DISPLAY

摘要

The technique provides a waveguide display with a compact projection light engine and a diffractive waveguide. Diffraction waveguides include input diffraction gratings with rolled k-vectors. The projection light engine provides the collimating light to the projected exit pupil outside the diffraction waveguide. Projection light engine components may include a light (or illumination) source, a microdisplay, a lenticular screen, a doublet, a polarizing beam splitter (PBS), a clean-up polariser, a fold mirror, is. A method for fabricating a diffractive waveguide includes providing input grids with rolled k-vectors. The rays of light are diffracted by the master hologram to form the input diffraction gratings of the radiation substrate, and pass through the master hologram. The second radiation substrate may likewise be formed of different master holograms. A plurality of radiation substrates may be assembled to form a multi-layer diffraction waveguide (or multiple diffraction waveguides) having input diffraction gratings with increased diffraction efficiency and angular bandwidth.