Methods of optimizing and evaluating geometrical lightguides with microstructure mirrors for augmented reality displays

Waveguide or lightguide technology has been widely used in the state-of-the-art, see-through, near-eye displays to reduce system weight and form factor. Although a few of the current products use a geometrical lightguide as an optical combiner, its design and performance assessment methods have been barely discussed. In this paper, by taking into account the factors affecting retinal image quality, we presented novel methods for quantifying and evaluating the optical performances and artifacts of geometrical lightguides based on microstructure mirror arrays, and proposed new merit functions and a novel process for systematic optimization of such lightguides. A lightguide design example implementing the evaluation and optimization methods are demonstrated, and the resulted lightguide is then further utilized as a combiner for the design of a lightweight, glasses-like, see-through, neareye display.