Multispectral Imaging via a Thermally Tunable Reflective Planar Lens

Multispectral imaging plays a crucial role in simultaneously capturing detailed spatial and spectral information, which is fundamental for understanding complex phenomena across various domains. Traditional systems face significant challenges, such as large volume, static function, and limited wavelength selectivity. Here, we propose an innovative dynamic reflective multispectral imaging system via a thermally responsive cholesteric liquid crystal based planar lens. By employing advanced photoalignment technology, the phase distribution of a lens is imprinted to the liquid crystal director. The reflection band is reversibly tuned from 450 nm to 750 nm by thermally controlling the helical pitch of the cholesteric liquid crystal, allowing selectively capturing images in different colors. This capability increases imaging versatility, showing great potential in precision agriculture for assessing crop health, noninvasive diagnostics in healthcare, and advanced remote sensing for environmental monitoring.