Fabrication feasibility of high-quality SRG waveguides for augmented reality applications

We report successful development of surface-relief gratings (SRGs) engineered for next-generation augmented reality (AR) waveguides. By leveraging Displacement Talbot lithography (DTL) alongside dry etching of high-quality titanium dioxide (TiO₂) films, we establish a robust fabrication process. The integration of precise optical patterning through DTL and advanced dry etching techniques enables the reliable production of high-fidelity, high-performance gratings with precise design control. We present detailed lithography characterization and grating morphology results, confirming accurate replication of photomask designs into TiO₂ gratings with well-controlled taper angles, depths, duty cycles, and flat-bottom profiles, which are key features for efficient light coupling and guiding in AR waveguides. This approach supports the importance of mature process development, repeatable processes, and reliable optimization, laying a foundation for the integration of reproduceable and scalable SRG waveguides in modern AR systems.