Additive full-wafer fabrication of all-inorganic metalenses, waveguides, and diffractive optics for visible and IR applications via direct nanoimprint lithography

Full wafer scale fabrication of high-efficiency, all-inorganic optical devices including metalenses, AR/VR waveguides, and polarization-controlled holograms is demonstrated by using additive nanoimprint lithography with nanoparticle dispersion-based inks. Approximately one-thousand 4-mm-sized metalenses are fabricated per 8-inch wafer with high optical efficiency and excellent uniformity across the wafer. The absolute and relative efficiencies of the metalenses are more than 80% and 90%, respectively, which are approximately 95% of the maximum simulated efficiencies for this specific design. The close agreement between simulated and realized efficiencies indicates that future improvements are possible, and actual efficiencies are not limited by materials or process. The fabrication of polarization-sensitive, phase/amplitude-controlled holograms demonstrates that our process is capable of replicating asymmetric nanostructures with high aspect ratios of more than 10 by direct imprinting without etching. The imprinted metalenses are free from organics due to a post-imprint calcination step and exhibit outstanding dimensional and optical stabilities, as confirmed by accelerated environmental testing (ASTM G155). Refractive index of the structures can be increased up to 2.3 using a short post-imprint atomic layer deposition process. This work opens a path for true, full-scale additive manufacturing of meta-optics.