Characterization of Monolithic All-Dielectric Pixelated Optical Wave-Plate Arrays Fabricated by Nanoimprint Lithography

In this work, we present the successful characterization of a monolithic all-dielectric pixelated optical wave-plate array, fabricated by leveraging UV-nanoimprint lithography and a nano-trench-filling technique. The wave-plate array consists of repeat units, each containing four sub-pixels functioning as true zero-order quarter wave-plates, optimized for a wavelength of approximately 450 nm. Each sub-pixel measures 10μm x 10μm, and the wave-plate is constructed from silicon dioxide and titanium dioxide on a fused silica substrate. The trench-filled nano-grating structure exhibits form-birefringence, leading to robust mechanical, thermal, and optical properties. This innovative design overcomes limitations associated with traditional wave-plate fabrication techniques and offers potential applications in imaging polarimetry, dynamic interferometry, and fiber-optic telecommunications. Rigorous coupled-wave analysis was employed to optimize the design, and atomic layer deposition was used to fill the nano-trenches, creating a planarized surface suitable for further integration. Our results demonstrate the feasibility of pixelated optical retarder arrays with precise control over sub-pixel optical axis orientations, opening new avenues for integrated optics systems.