Design of a large field-of-view two-dimensional geometrical waveguide

Abstract

Geometrical waveguide has great advantages over conventional imaging systems, like larger field of view, larger exit pupil area, lower thickness and lighter weight. Two-dimensional (2D) geometrical waveguide can expand the vertical and horizontal pupil simultaneously, thus becoming a mainstream solution for commercial applications. The transmission path of two-dimensional optical system is more complicated and therefore the stray light in two-dimensional geometrical waveguide is more complex compared with one-dimensional waveguide. In this paper, the causes of stray light in 2D geometrical waveguide are discussed based on the non-sequential ray-tracing with detailed numerical analysis and the targeted solutions are developed to effectively improve the imaging quality. Consequently, a stray-light-free design of geometrical waveguide is proposed having the field of view reaching 49° × 56° with 22.6 mm × 26 mm eye box at 20 mm eye relief.