SBIR-STTR Award

Applied Quantum Technologies along with its university partner Duke University propose a coded-aperture, multi-aperture snapshot Raman imager. By combining an innovative optical design and advanced compressed sensing algorithms, a snapshot system provides dwell times much shorter than conventional slit-based or tunable-filter based spectral imagers. A short-wave infrared excitation source allows for minimal sample fluorescence, making the system able to cope with target signatures in a wide variety of backgrounds. While the majority of Raman systems available are point-based, having imaging capabilities permits wide area coverage at a fraction of the time of point-based systems. By utilizing compressed sensing algorithms, large amounts of spatial and spectral information can be acquired using the limited pixel counts available to short-wave infrared detector arrays.

Keywords:
Raman Spectroscopy, Spectral Imaging, Coded Apertures, Compressed Sensing

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.

Keywords:
Spectral Imaging;Raman Spectroscopy;Standoff Chemical Imaging;Compressive Sensing