A Spatiotemporal Tunable Filter Array Chip for Video-Rate Hyperspectral Imaging

Existing miniaturized spectral imagers have mutual restrictions among spatial, temporal, and spectral resolutions, making them inadequate to meet practical needs. Here, we demonstrate a spatiotemporal filter array chip to tackle the trade-off among the three resolutions for miniaturized hyperspectral imaging. A 2 × 2 Fabry-Perot filter array is embedded inside a tunable liquid crystal spectral modulator, increasing the number of filtering channels spatiotemporally in hardware, which empowers the spectral imager with high spatial, temporal, and spectral resolutions simultaneously. The tunable filter is of transmission type with the advantages of easy fabrication and large modulation. Experimental results show the proposed spectral imager has a spectral resolution of around 0.5 nm in the visible range, with a frame rate of 60 Hz and a spatial resolution of up to 25 lp/mm without postinterpolation. The proposed filter gives the best balanced performance for spectral imaging in terms of spatial, temporal, and spectral resolutions.