We developed the theoretical model of the time-resolved thermal lens spectroscopy of a single particle with various pulse shape optical excitations. To account for the pulse shape optical excitation in the model, a heat diffusion equation of two media (the particle and liquid solvent) is solved using the numerical Laplace transform method. The model also incorporates the propagation of a diffracted Gaussian probe beam due to the thermal lens effect. Numerical results are presented to illustrate the effects of the excitation pulse shape and probe beam size on the evolution of the photothermal lens signal. The developed model is utilized for the thermal diffusivity and size extraction of a red polystyrene particle.
© 2010 Optical Society of America
Original Manuscript: October 12, 2009
Revised Manuscript: February 4, 2010
Manuscript Accepted: February 4, 2010
Published: March 31, 2010
Marta Andika, George Chung Kit Chen, and Srivathsan Vasudevan, "Excitation temporal pulse shape and probe beam size effect on pulsed photothermal lens of single particle," J. Opt. Soc. Am. B 27, 796-805 (2010)