Multi-Resonant Metasurfaces for Full-Spectrum Wavefront Engineering and Hyperspectral Imaging

Pin Chieh Wu^1*

¹Department of Photonics, National Cheng Kung University, Tainan, Taiwan

* Presenter:Pin Chieh Wu, email:pcwu@gs.ncku.edu.tw

Metasurfaces with multi-resonant properties offer new potential for broadband photonic applications beyond conventional narrowband devices. Here, we present a multifunctional metasurface architecture that co-designs subwavelength-scale meta-atoms with a customized distributed Bragg reflector (DBR), yielding a spectrum of high-Q optical resonances covering visible to near-infrared wavelengths. We demonstrate that this platform can be harnessed for full-spectrum wavefront engineering, including precise phase and amplitude control[1]. This facilitates diverse optical operations such as dynamic structural color rendering, polarization-dependent holography, and information security through optical encryption. Importantly, we further implement the same multi-resonant principle in an off-axis focusing configuration to realize a planar hyperspectral imaging system. This compact device eliminates the need for traditional bulky dispersive optics by encoding spectral content into spatially resolved signals. To extract high-resolution spectral data from this minimal hardware setup, we integrate a CODE (convex/deep) algorithm that reconstructs hyperspectral images from limited measurement data[2]. This approach not only reduces acquisition complexity but also maintains imaging fidelity and spectral accuracy. Together, these innovations showcase a unified optical platform capable of delivering multifunctional wavefront modulation and hyperspectral data capture. Our work suggests that such metasurfaces can serve as compact, efficient, and scalable components in advanced imaging, sensing, and communication systems, bridging the gap between nanophotonic design and real-world photonic integration.

Reference
1. S.-H. Huang, H.-P. Su, C.-Y. Chen, Y.-C. Lin, Z. Yang, Y. Shi, Q. Song, and P. C. Wu, "Microcavity-assisted multi-resonant metasurfaces enabling versatile wavefront engineering," Nature Communications 15, 9658 (2024).
2. C.-H. Lin, S.-H. Huang, T.-H. Lin, and P. C. Wu, "Metasurface-empowered snapshot hyperspectral imaging with convex/deep (CODE) small-data learning theory," Nature Communications 14, 6979 (2023).

Keywords: Multi-resonant metasurface, Wavefront control, Hyperspectral imaging, Optical encryption, Plasmonics