Progress Toward a Better Understanding of Signal Generation Processes in the Laser‐Excited Photothermal Spectroscopy of Homogeneous Samples
Trends in Analytical Chemistry
This article examines some recent experiments and theories that have advanced our understanding of the physical effects following thermal relaxation of the excited state. Experiments which show that the temperature-dependent refractive index is composed of density and pure-thermal terms are discussed. The importance of the purely thermal term is that it allows ultra-fast pulsed excitation sources to be used in photothermal refraction spectroscopy. This opens up new areas of applications in ultra-fast measurement. The effect of and progress towards the elucidation of specific volume changes are reviewed. Finally, recent progress in understanding nonlinear optical absorption and its effect on the photothermal signal are summarized.
Progress Toward a Better Understanding of Signal Generation Processes in the Laser‐Excited Photothermal Spectroscopy of Homogeneous Samples Stephen E. Bialkowski Trends in Analytical Chemistry 17 520‐532 1998