Design and Fabrication of Narrowband Metalens for Mobile 3D Sensing (ART/385CP)

For continuously miniaturized devices, especially for mobile 3D sensors, the need for more compact, thinner, and more efficient optical lenses is increasing. Compared with traditional optical lenses, a metalens is fabricated by semiconductor processing techniques and has only single layer of planar nanoscale structure, making it the next generation of the flat optical element and better suited to the needs of miniaturized devices. However, due to the combination of geometrical optics and physical optics, the current design process for the metalens is complex and requires multiple optics software. In this project, narrowband metalenses will be designed. Through collaboration with universities and industries, the metalens fabrication process and material selection will be studied, aiming to develop more compact mobile 3D sensors, including structured-light projection metalens and structured-light imaging metalens for structured-light 3D sensor, ToF flood-light projection metalens and time-of-flight (ToF) imaging metalens for ToF 3D sensor. Besides, based on the design experience gained in this project, the narrowband metalens design automation (MDA) tools will be developed to simplify the design process of the metalens. During the project, the metalens will be designed according to the flow path: (1) calculation of optical properties of nanostructures, (2) selection of metacells, (3) design of phase maps, (4) metalens generation, and (5) metalens verification. This project will also develop the metalens fabrication process and material research for the metalens, and realize proof of concept, know-how accumulation and test of new materials in the metalens fabrication through university collaboration. The metalens will be fabricated by semiconductor micro and nano processes, which are based on, but not limited to, photolithography, electron beam exposure and nanoimprint processes. The developed MDA tools will render faster optimization of the metacell, accelerated iteration process, and one-station narrowband metalens design. This project will upgrade local technology development by providing new narrowband metalens design & fabrication solutions for the industry. Achievement of this project will facilitate the establishment of local nano-photonic design-fabrication eco-system, contributing to the re-industrialization of Hong Kong. In the long term, this project will establish ASTRI's technology leadership in nano-photonic and boost semiconductor-related technologies development for Hong Kong and Greater Bay Area (GBA).