The paper "Ultraspectral Imaging Based on Metasurfaces with Freeform Shaped Meta-Atoms" by PhD student Jiawei Yang and others was published in Laser & Photonics Reviews (IF 13.138), on May 20, 2022 ( https://doi.org/10.1002/lpor.202100663).

Optical metasurfaces can flexibly manipulate the phase, amplitude, polarization, spectrum and other parameters of light. However, meta-atoms, or unit cells, of metasurfaces are conventionally designed using regular shapes, limiting the improvement of the performance. Following our previous work of the world-first real-time ultraspectral imaging chip published in Optica, our group proposed an novel ultraspectral imaging chip based on metasurfaces with freeform shaped meta-atoms in this work, which can break through the design limitation of regular shapes and expand the design space of metasurfaces. The metasurface modulation units based on freeform shaped meta-atoms possess more abundant Bloch modes, which improves the diversity of the transmission spectra, and further improves the spectral reconstruction accuracy and spectral resolution. The reconstruction results of broadband spectra and narrowband spectra show that the proposed ultraspectral imaging chip can achieve the reconstruction of broadband spectra with a fidelity over 99% and a wavelength resolution of 0.5 nm, and the standard deviation of central wavelength deviations for narrowband spectral reconstruction is only 0.024 nm. This work further improves the performance of metasurface-based spectral imaging chips, and promotes their development and applications in the field of real-time sensing.

Jiawei Yang, Kaiyu Cui,* Xusheng Cai, Jian Xiong, Hongbo Zhu, Shijie Rao, Sheng Xu, Yidong Huang,* Fang Liu, Xue Feng, and Wei Zhang, Ultraspectral Imaging Based on Metasurfaces with Freeform Shaped Meta-Atoms. Laser & Photonics Reviews 2022, 2100663. https://doi.org/10.1002/lpor.202100663