Optical computation of chemometrics projections using a digital micromirror device

We present an approach to perform chemometrics computations optically using a digital micro-mirror device (DMD) coupled with a near infrared source and diffraction grating. The DMD can be configured to project specific wavelengths onto (or away from) a detector. We show how to program the DMD to perform linear operations (i.e., inner products) on chemical spectra, thus avoiding the need for additional processing. We validate the approach on two chemical discrimination problems using linear discriminant analysis (LDA). Our results show that computing the LDA projections optically yields higher signal-to-noise ratio, and therefore improved discrimination, than performing it digitally (e.g., after scanning the full spectra). The approach is general and can be applied to other chemometrics problems beyond discrimination.