Uniformity control of large area diffraction gratings for augmented reality surface relief waveguide masters

Abstract

Larger field of view, better image quality and higher efficiency in Augmented Reality (AR) glasses demands masters with large uniform diffraction gratings. Typically, a surface relief waveguide master is composed of input, output and deflection/expander gratings which all can either be slanted, blazed or binary gratings. Control of the angle of slanted and blazed gratings especially over large areas is an important parameter towards high quality large area gratings. Here we demonstrate large area diffraction gratings for AR applications where the angle uniformity is demonstrated to be +/- 1 degree across an 8-inch wafer. NIL technology has been pioneering the development of high quality large area slanted, binary and blazed grating masters and offers customizable solutions for all of the above-mentioned types of gratings and the gratings can be combined with 100% design freedom on the masters.