Waveguides having integrated spacers, waveguides having edge absorbers, and methods for making the same

Abstract

In some embodiments, a head-mounted, near-eye display system comprises a stack of waveguides having integral spacers separating the waveguides. The waveguides may each include diffractive optical elements that are formed simultaneously with the spacers by imprinting. The spacers are disposed on one major surface of each of the waveguides and indentations are provided on an opposite major surface of each of the waveguides. The indentations are sized and positioned to align with the spacers, thereby forming a self-aligned stack of waveguides. Tops of the spacers may be provided with light scattering features, anti-reflective coatings, and/or light absorbing adhesive to prevent light leakage between the waveguides. As seen in a top-down view, the spacers may be elongated along the same axis as the diffractive optical elements. The waveguides may include structures (e.g., layers of light absorbing materials, rough surfaces, light out-coupling optical elements, and/or light trapping microstructures) along their edges to mitigate reflections and improve the display contrast.