Snapshot Raman Spectral Imager

Applied Quantum Technologies proposes the development of a snapshot Raman spectral imager for chemical imaging applications with a 1-5 meter standoff. Standoff chemical imaging methods are typically point-based, making scan times impractical for situations where a wide area needs to be surveyed. The high spectral resolution needed to take advantage of the specificity of Raman spectroscopy limits the use of traditional slit-based or tunable-filter based spectral filters. By implementing coded-aperture snapshot spectral imaging (CASSI), AQT"s instrument will be able to operate in two modes--- a large-area coarse resolution scan mode, and a high-resolution region-of-interest mode. Real-time algorithms will process the sensor data into chemical image maps that will be super-imposed on a visible image of the scene. A low power deep-UV gas laser at 248.6 nm will provide the excitation to assure no background fluorescence, and an intensified camera will provide high sensitivity image acquisition. The deep-UV operation allows for daylight operation due to the upper atmospheric absorption of deep-UV light. Custom excitation, collection, and spectrograph optics provide a compact, high-throughput optical path.