Metasurface-driven full-space structured light for three-dimensional imaging

TLDR

Structured light depth‑sensing uses dot arrays to capture 3D information, but conventional diffractive optics are limited by micron‑scale pixel size, restricting field of view and diffraction efficiency. The authors propose a metasurface‑enhanced structured light platform that scatters a high‑density ~10 K dot array across a 180° field of view. They achieve this by manipulating light at subwavelength scales, demonstrating a proof‑of‑concept with face masks 1 m apart and stereo matching, and enabling high‑throughput replication via nanoparticle‑embedded‑resin imprinting on arbitrary substrates. The resulting full‑space diffractive metasurface offers an ultra‑compact depth‑perception platform suitable for face recognition and automotive robot vision.

Abstract

Structured light (SL)-based depth-sensing technology illuminates the objects with an array of dots, and backscattered light is monitored to extract three-dimensional information. Conventionally, diffractive optical elements have been used to form laser dot array, however, the field-of-view (FOV) and diffraction efficiency are limited due to their micron-scale pixel size. Here, we propose a metasurface-enhanced SL-based depth-sensing platform that scatters high-density ~10 K dot array over the 180° FOV by manipulating light at subwavelength-scale. As a proof-of-concept, we place face masks one on the beam axis and the other 50° apart from axis within distance of 1 m and estimate the depth information using a stereo matching algorithm. Furthermore, we demonstrate the replication of the metasurface using the nanoparticle-embedded-resin (nano-PER) imprinting method which enables high-throughput manufacturing of the metasurfaces on any arbitrary substrates. Such a full-space diffractive metasurface may afford ultra-compact depth perception platform for face recognition and automotive robot vision applications.