Compact miniature snapshot imaging spectrometry using continuous variable filter

Snapshot spectral imaging is a cutting-edge parallel acquisition technology for mapping the 3D datacube (2D spectral and 1D spatial information) of a scene in real time. Herein, we present a compact, miniature, snapshot Optically Replicating and Remapping Imaging Spectrometer (ORRIS). Its principle is based on the shifting of subimages replicated by a specially organized lenslet array and the filtering of each subimage by a continuous variable filter (CVF). The 3D datacube is recovered just using a simple image remapping process. The use of the lenslet array and the CVF makes the system very compact and miniature. A handheld proof-of-principle prototype is built in our laboratory by just using commercial-off-the-shelf products. It covers a wavelength region 360 nm to 860 nm with 80 spectral channels with a spatial resolution of 400 × 400 pixels. The volume of prototype is about 230 mm (length) × 70 mm (width) × 70 mm (height) and the weight is about 1.0 kg for finite imaging, and it will become 50 mm (length) × 70 mm (width) × 70 mm (height) and 0.5 kg for infinite imaging. The prototype is verified by measuring outdoor static and dynamic scenes.