Volatile Compounds Detection by IR Acousto-Optic Detectors

Many important gasses and liquids, including the aggressive or anomalous ones for which our attention is higher, have strong absorption lines in the near and mid infrared spectral range. Infrared sensors exploit the fact that most gasses and liquids present unique infrared signatures in the 2-14 um wavelength region. Due to this uniqueness infrared sensors provide conclusive identification and measurement of the target sample with little interference from other unwanted volatile compounds. Infrared sensors have the characteristics of being highly accurate, reliable, and, in general, low noise devices. In this chapter we will consider the most important infrared sources and sensors as well as the absorption techniques employed in this context. Furthermore the acousto-optic principle will be presented and discussed in some detail as the promoter of a multi-wavelength infrared generator. Finally system performance and data on gas detection will also be introduced and commented upon