THERMAL EMISSION DECAY FOURIER-TRANSFORM INFRARED-SPECTROSCOPY

We present a new technique, thermal emission decay Fourier transform i nfrared spectroscopy, designed to perform noninvasive, noncontacting a bsorption spectrum measurements on unprepared, arbitrary surfaces. It uses pulsed optical heating of the near-surface region of the sample t o produce transient thermal emission spectra in the midinfrared spectr al region for room temperature samples. The raw data of intensity vers us path difference versus time after excitation can be processed in tw o ways; (1) to yield time-resolved spectra for depth profiling of laye red samples; and (2) to yield decay-associated spectra for absolute ab sorbance measurements of homogeneous samples. (C) 1995 American Instit ute of Physics.