Abstract

This work presents a theoretical study of a heat transfer effect, taking into account the heat transfer within the heated sample and out to the surrounding medium. The analytical solution is used to model the thermal lens and thermal mirror effects and the results are compared with the finite element analysis (FEA) software solution. The FEA modeling results were found to be in excellent agreement with the analytical solutions. Our results also show that the heat transfer between the sample surface and the air coupling fluid does not introduce an important effect over the induced phase shift in the sample when compared to the solution obtained without considering axial heat flux. On the other hand, the thermal lens created in the air coupling fluid has a significant effect on the predicted time-dependent photothermal signals. When water is used as fluid, the heat coupling leads to a more significant effect in both sample and fluid phase shift. Our results could be used to obtain physical properties of low optical absorption fluids by using a reference solid sample in both thermal lens and thermal mirror experiments.

Heat coupling effect on photothermal detection with a moving Gaussian excitation beam

Jingtao Dong and Rongsheng Lu
Appl. Opt. 58(31) 8695-8701 (2019)

Time-resolved thermal lens spectroscopy with a single-pulsed laser excitation beam: an analytical model for dual-beam mode-mismatched experiments

Mohammad Sabaeian, Hamidreza Rezaei, and Abdolmohammad Ghalambor-Dezfouli
Appl. Opt. 56(4) 999-1005 (2017)

Pulsed photothermal mirror technique: characterization of opaque materials

O. A. Capeloto, G. V. B. Lukasievicz, V. S. Zanuto, L. S. Herculano, N. E. Souza Filho, A. Novatski, L. C. Malacarne, S. E. Bialkowski, M. L. Baesso, and N. G. C. Astrath
Appl. Opt. 53(33) 7985-7991 (2014)

Top-hat cw-laser-induced time-resolved mode-mismatched thermal lens spectroscopy for quantitative analysis of low-absorption materials

Nelson G. C. Astrath, Francine B. G. Astrath, Jun Shen, Jianqin Zhou, Paulo R. B. Pedreira, Luis C. Malacarne, Antonio C. Bento, and Mauro L. Baesso
Opt. Lett. 33(13) 1464-1466 (2008)

Time-resolved thermal mirror technique with top-hat cw laser excitation

Francine B. G. Astrath, Nelson G. C. Astrath, Jun Shen, Jianqin Zhou, Luis C. Malacarne, P. R. B. Pedreira, and Mauro L. Baesso
Opt. Express 16(16) 12214-12219 (2008)