Depolarized Infrared Reflectance from Dry and Wetted Surfaces

摘要

Backscattering of the carbon dioxide laser was measured from soil, sand, concrete, asphalt, and military-specified painted metal plates before and after contamination by an infrared-absorbing liquid. Sensitivity of the 9- to 11-micrometer volume reflectance spectra to the targeted liquid contamination differed significantly between porous and nonporous scattering surfaces, indicating that diffusion of liquid the material bulk, not resonant absorption of the probe laser by the liquid, dictates direct detection sensitivity thresholds.