Optical fiber Fourier transform infrared evanescent wave spectroscopy has been used to remotely detect solid aluminum hydroxide Al(OH)3. This compound is a principal corrosion product of aluminum. The strongest mid-infrared spectral features of Al(OH)3 are found between 3350 cm-1 and 3650 cm-1. Identification of five aluminum hydroxide absorption features in this spectral region has been made. The relative positions, transition strengths, and widths of the recorded bands are in agreement with reference data. The experimental arrangement included a 4 cm-1 resolution Michelson interferometer equipped with an InSb detector and an optical accessory to match the optical fibers to the interferometer spectrometer. Detection of aluminum hydroxide using optical fiber FTIR evanescent wave spectroscopy is an important step in the development of a technique for the remote detection of corrosion products of aluminum.
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