An optically-encoded mechanical modulation system and an electrical signal extraction algorithm are introduced. The system employs the beam chopping in a highly parallel scheme to impart multiple modulation channels onto the spectrum of a white-light source. The optically-multiplexed beam is directed through an experimental sample, and the absorption of the sample at each of the individual modulation channel wavelengths is resolved. A MATLAB-based parallel frequency-selection algorithm is ultimately used to resolve the signals. The low-noise benefits of optical lock-in detection and the practicality of parallel encoding/extraction are demonstrated in this design.
Experimental Design and Algorithmics for a Multichannel Spectral Data Acquisition System
Duerr, K., Seethaler, R. J., and Holzman, J. F. (August 19, 2009). "Experimental Design and Algorithmics for a Multichannel Spectral Data Acquisition System." ASME. J. Dyn. Sys., Meas., Control. September 2009; 131(5): 051011. https://doi.org/10.1115/1.3155014
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