A complete and general theoretical description of dual-beam photothermal lensing spectroscopy is given. The results are valid for the most general conditions, that is, for flowing as well as stationary media, and for cw as well as pulsed excitation. For pulsed excitation, the results are valid for arbitrary pulse length. The cw results apply to both modulated as well as unmodulated excitation. Both transverse and collinear geometries are considered.
© 1988 Optical Society of America
Reeta Vyas and R. Gupta, "Photothermal lensing spectroscopy in a flowing medium: theory," Appl. Opt. 27, 4701-4711 (1988)