Integration of wafer and plate-based NIL for scalable manufacturing of high-quality AR waveguides

One of the critical components of Augmented Reality (AR) glasses is the optical waveguide. Various manufacturing methods for waveguides are currently being investigated, predominantly based on the well-established wafer-based value chain. In this study, we propose an alternative approach that combines the wafer-based value chain with the high-volume, low-cost manufacturing capabilities of large-area Roll-to-Plate (R2P) Nanoimprint Lithography (NIL). This approach demonstrates the upstream and downstream process compatibility of large-area NIL. To validate this, we developed a diffractive waveguide design featuring multi-depth slanted gratings with a 25&deg; slant angle. This design addresses the refractive index mismatch between the substrate and the nanograting resin. We utilized multiple ultra-flat high-refractive-index glass wafers (<i>n</i> = 2.0) with 200mm diameter, paired with solvent free and solvent containing resins (<i>n</i> = 1.9). Our results showcase the scalability and quality of this method using a carrier-based imprint (Gen3 panel size, 550mm &times; 650mm), enabling the simultaneous imprinting of five 200mm wafers, each containing four waveguides, in a single cycle.