US Patent 11662590 Holographic waveguide eye tracker

An eye tracker having a first waveguide for propagating illumination light along a first waveguide path and propagating image light reflected from at least one surface of an eye along a second waveguide path. At least one grating lamina for deflecting the illumination light out of the first waveguide path towards the eye and deflecting the image light into the second waveguide path towards a detector is disposed adjacent an optical surface of the waveguide.