COMPACT PROJECTION LIGHT ENGINE FOR A DIFFRACTIVE WAVEGUIDE DISPLAY

摘要

The technology provides a waveguide display having a compact projection light engine and a diffractive waveguide. The diffractive waveguide includes input diffraction gratings with rolled k vectors. The projection light engine provides collimating light to a projected exit pupil external to the diffractive waveguide. The projection light engine components may include a light (or illuminating) source microdisplay lenticular screen doublet polarizing beam splitter (PBS) clean up polarizer fold mirror curved reflector and quarter waveplate. A method of manufacturing a diffractive waveguide includes providing input gratings with rolled k vectors. Rays of light are diffracted by and passed through a master hologram to form input diffraction gratings of a copy substrate. A second copy substrate may likewise be formed with a different master hologram. Multiple copy substrates may be assembled to form a multi layer diffractive waveguide (or multiple diffractive waveguides) having input diffraction gratings with increased diffraction efficiency and angular bandwidth.