Sensing Infrared Fiber Evanescent Wave Spectroscopy

2 Sensing Infrared Fiber Evanescent Wave Spectroscopy 

FEWS sensors are similar to ATR spectrometers however, unlike standard ATR crystals, the elongated configuration of the fiber ensures a longer waveguide/medium. This in turn generates a larger number of internal reflections, thus enhancing detection sensitivity. 

The experimental setup for FEWS consists of an FTIR spectrophotometer coupled with an IR fiber and a mercury cadmium telluride (MCT) detector [Fig. 7.10a). The signal is collected on a computer and interpreted using conventional spectral analytical tools. 

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