The paper "Angle-Insensitive Spectral Imaging Based on Topology-Optimized Plasmonic Metasurfaces" by postdoc Jiawei Yang, associate professor Kaiyu Cui and others was published in Laser & Photonics Reviews, a prestigious international journal in the field of optics, on June 27, 2024 (https://doi.org/10.1002/lpor.202400255).

Our research group has previously proposed on-chip spectral imaging based on broadband spectral modulation of metasurfaces and computational spectral reconstruction, which provides a promising scheme for portable spectral cameras. However, the angular dependence of silicon-based metasurface units leads to the angular sensitivity of spectral imaging. In this work, we utilize metal instead of dielectric materials to realize on-chip angle-robust computational spectral imaging based on a group of topology-optimized plasmonic metasurface units under a 30° field-of-view, and demonstrate angle-insensitive spectral imaging in the wavelength range of 450 to 750 nm. Furthermore, we experimentally verified the angle-insensitive spectral filtering effects of the fabricated metasurface units, and demonstrated angle-robust spectral reconstruction with a fidelity of over 98% as well as spectral imaging for a standard color checker.

This work potentially expands the application fields of on-chip spectral imaging. With larger angle tolerance, spectral imaging chip can be assembled with wide-angle lens for large field-of-view imaging or tilt-shift lens for off-axis imaging, and be potentially used in smartphones, digital cameras and other consumer electronic devices. In addition, we firstly utilizes metal instead of dielectric materials to realizing on-chip computational spectral imaging, which paves the way for metal-based on-chip multimodal imaging with dimension of depth, polarization, spectrum and so on.

Jiawei Yang, Kaiyu Cui,* Yidong Huang,* Wei Zhang, Xue Feng, and Fang Liu, Angle-Insensitive Spectral Imaging Based on Topology-Optimized Plasmonic Metasurfaces. Laser & Photonics Reviews 2024, 2400255. https://doi.org/10.1002/lpor.202400255