Real-time hyperspectral imaging with volume holographic optical elements

We report a novel hyperspectral optical sensor capable of providing image information with four degrees of freedom (4D), ie, volumetric spatial information and spectral information simultaneously, in real time. The imaging principle is based on the diffraction properties of volume holographic optical elements designed as spatial-spectral filters. The 4D imager can be configured to image objects in spatial scales ranging from meters to micrometers. The imager also enables feature matching in all four dimensions, which improves the information-extraction capabilities from the image data. We report experimental results and theoretical estimates on the image quality attainable by the 4D imager.