Single-Shot Hyperspectral Imaging of Weakly Ionized Plasma and Chemiluminescence Emissions

A compressed sensing based single-shot hyperspectral imaging system composed of a PI 2300i spectrometer, a PI-MAX4 ICCD camera, a Texas Instruments Light Crafter 4500 Digital Micromirror Device (DMD) and collection optics has been implemented on hyperspectral imaging of emissions from glow discharge and flame. The raw three-dimensional (3D) hyperspectrum from the emissions, consisting of two-dimensional spatial and one-dimensional spectral information, was first encoded by a random binary pattern from the DMD, and then compressed by the spectrometer into a coded 2D spectral image. The hyperspectrum then can be computationally reconstructed from the coded 2D spectral image with the coding pattern, restoring intensity at each voxel of the 3D hyperspectrum. Hyperspectra of the emissions of weakly ionized air and a methane-air flame were measured, the results agree to conventional spectroscopic measurements. The compressed single-shot hyperspectral imaging technique will provide highly efficient high-speed spectroscopic measurements on plasmas and other reactive systems.