Compact snapshot optically replicating and remapping imaging spectrometer (ORRIS) using a focal plane continuous variable filter

Snapshot spectral imaging is a cutting-edge parallel acquisition technique to acquire the three-dimensional (3D) datacube (x, y, λ) in real time. In this letter, a novel snapshot spectral imaging technique, Optically Replicating and Remapping Imaging Spectrometer (ORRIS), is presented. It is based on the combination of the shifting of subimages replicated by a specially designed lenslet array (LA) and the filtering of each subimage by a focal plane continuous variable filter (CVF). The 3D datacube is recovered just using a simple image remapping process. The use of the LA and the focal plane CVF makes the system compact and miniature, and achieves hyperspectral imaging. A handheld proof-of-principle prototype is built. The ORRIS prototype covers a Vis/NIR wavelength region 380 to 860 nm with 80 spectral channels with a spatial resolution of 400 × 400 pixels. The prototype is validated by measuring outdoor static and dynamic scenes.