Submillimeter spectroscopy for chemical analysis with absolute specificity

Abstract

A sensor based on rotational signatures in the submillimeter (SMM) region is described. This sensor uses frequency synthesis techniques in the region around 10 GHz, with nonlinear diode frequency multiplication to 210-270 GHz. This provides not only a nearly ideal instrument function, but also frequency control and agility that significantly enhance the performance of the spectrometer as a sensor. The SMM frequencies provide significantly stronger absorptions and broader spectroscopic coverage than lower-frequency microwave systems. Among the characteristics of the sensor are absolute specificity, low atmospheric clutter, good sensitivity, and near-term paths to systems that are both compact and very inexpensive.