Multishot hyperspectral imaging based on tunable diffractive lenses

Hyperspectral imaging systems are widely used for their convenient way of capturing 3D information. The coded aperture snapshot spectral imaging (CASSI) systems and diffractive optical element (DOE)-based hyperspectral imaging systems are two types. CASSI systems can deal with the underdetermined inverse problem from a single-shot acquisition and further improve the quality of reconstructed results by utilizing multiple measurements; however, the systems based on DOEs cannot change the point spread function (PSF) encodings after DOEs are designed. Inspired by the tunable Moiré lens, we propose a multishot DOE-based hyperspectral imaging system that utilizes the mutual rotation between two DOEs to realize the change of the PSF encodings and enables multiple measurements. Our system can snapshot similar to fixed DOE-based systems. Meanwhile it requires only rotation and achieves the variable PSF encodings without moving along the horizontal and vertical axes. Moreover, our DOEs have a more regular and controllable dispersion. With the spectral reconstruction algorithm, the simulation results show that increasing measurements improves performance. We suggest a scheme to improve spectral accuracy by changing DOE encodings for multiple measurements.