SBIR-STTR Award

OPTRA proposes an open-architecture spectral gas sensor based on compressive sensing concepts employed for both spatial and spectral domains. Our matched spectral filter (MSF) core can be used as a single point detector in either point or standoff configurations or it can be coupled with a compressive imaging module for molecular imaging. The MSF core employs a digital micromirror device (DMD) to apply reference spectra to a spatially dispersed spectrum; the dot product measured with a single element photodetector is proportional to the probability of the compound corresponding to the reference spectrum being present. The MSF can also be used for quantification via grayscaling of the DMD. This approach effectively performs multicomponent spectral analysis in hardware rather than software thereby reducing data bandwidth requirements. The MFS will be designed for the 3-5.5 micron spectral range enabling detection and quantification of a range of greenhouse gases and other air pollutants. This solution represents a significant cost and size reduction relative to commercially available spectrometers operating in this spectral range, as it does not require a focal plane array or interferometer. Under the Phase I effort we will design, build, and test the MSF core configured for point detection.

OPTRA proposes the development of a modular, reconfigurable matched spectral filter (RMSF) spectrometer for the monitoring of greenhouse and volcanic gases. The heart of this spectrometer will be an RMSF core, which can be paired with different fore-optics or detector modules to achieve active point or passive standoff detection of the chemicals of interest. The RMSF core is comprised of a dispersive spectrometer that images the sample spectrum from 3 ? 5.5 micron onto a digital micro-mirror device (DMD) such that different columns correspond to different wavebands. By applying masks to this DMD, a matched spectral filter can be applied in hardware. This results in a highly flexible system that can address a wide variety of chemicals by simply updating the DMD masks applied and a wide variety of applications through modular hardware design. Use of the DMD and a single element detector in place of a conventional FPA results in significantly reduced cost and improved performance in terms of image uniformity, pixel operability, and dynamic range. The proposed Phase II effort will produce a prototype RMSF core with one set of fore-optic and detector modules for each of the two detection modalities.