Abstract
We present a metasurface imaging system capable of simultaneously capturing two images at close range (1-2 cm) and an additional image at long range (about 40 cm) on a shared photosensor. The close-range image pair focuses at 1.4 cm and 2.0 cm, respectively, which forms a focal stack, enabling passive ranging with an accuracy of ±1 mm from 12 mm to 20 mm through a computationally efficient depth-from-defocus algorithm for a simplified scenario. The entire system is compact, with a total track length of 15 mm, making it suitable for seamless integration into edge platforms for defense and other resource-constrained applications. By combining a multi-aperture metasurface with a refractive lens, the proposed system produces multiple sub-images with distinct focal distances, enabling both depth estimation and multi-range scene capture without mechanical scanning or multiple cameras.
Depth estimation performance of the prototype. The predicted depth closely follows the true depth, with the mean absolute error staying below 1 mm across the 12 to 20 mm operating range.
Optical layout of the proposed metasurface camera. Three apertures and a shared refractive lens create three sub-images at different focal distances on a common photosensor.
Representative sensor output for a scene with both near and far targets. The near object is resolved in the close-focus channels, while the far target is sharp in the long-range channel.
Prototype hardware layout showing the metasurface assembly, pinhole, lens, and photosensor in a compact 15 mm track length.
BibTeX
@article{Luo2025,
title={Compact single-shot ranging and near-far imaging using metasurfaces},
author={Luo, Junjie and Liu, Yuxuan and Chen, Wei Ting and Wang, Qing and Guo, Qi},
journal={Optical Engineering},
year={2025},
doi={10.1117/1.OE.64.3.033101}
}