Pulsed‐Laser Excited Differential Photothermal Deflection Spectrometry
This paper describes a differential photothermal optical absorbance apparatus that uses two excitation beams at different wave-lengths. A single probe beam monitors the difference in heats generated by the two wavelengths. The theory is developed for the operational principles of the apparatus, and theoretical signals are compared with those obtained with a conventional absorption spectrophotometer. The differential photothermal apparatus has a theoretical advantage over conventional spectrophotometry for samples with less than unit absorbance. Experiments are described which verify the operating principles and demonstrate the flexibility of the apparatus.
Pulsed‐Laser Excited Differential Photothermal Deflection Spectrometry Stephen E. Bialkowski, Xu Gu, Pete E. Poston, and Linda S. Powers Applied Spectroscopy 46 1335 1992