Diffractive-MEMS implementation of a Hadamard near-infrared spectrometer

This paper describes the implementation of an optically efficient near-infrared spectrometer using a diffractive-MEMS chip in combination with digital-transform methods. This spectrometer architecture offers potential advantages over conventional detector-array-based designs because the modulation inherent in the use of digital-transform spectroscopy not only permits the normal signal-to-noise improvements associated with modulation of the light source, but it also creates an inherent insensitivity to stray light. Sample applications, illustrated here for the specific case of the Hadamard digital transform, include material inspection and identification and the monitoring of dynamic processes, such as epoxy-resin cure.