PULSED PHOTOTHERMAL DEFLECTION SPECTROSCOPY WITH OPTICALLY DENSE SAMPLES

The pulsed photothermal deflection spectroscopy (PTDS) method to determine the large optical absorption coefficient from the transverse PTDS magnitude and to measure spectroscopic data of optically dense sample from the normal-to-transverse magnitude ratio of the PTDS signal is presented and has been examined both theoretically and experimentally. Saturation at high absorption, effects of thermal inhomogeneity of the sample, and energy or power fluctuation of both the excitation and probe beams are avoided by this method. Together with the transverse PTDS technique, the dynamic range of spectroscopic measurement is over 9 to 10 orders of magnitude. This technique can be used with sample which is transparent or semitransparent to the probe beam.