An analytical model for finite radius dual-beam mode-mismatched thermal lens spectroscopy

作者：Sabaeian Mohammad^*; Nadgaran Hamid

来源：Journal of Applied Physics, 2013, 114(13): 133102.

DOI：10.1063/1.4824295

In this work, a new model for dual-beam mode-mismatch thermal lens spectroscopy is presented. The model was based on a new analytical solution of time-dependent heat equation for finite radius cylindrical samples exposed to TEM00 excitation laser beams. The Fresnel diffraction integration method was used to calculate time-dependent on-axis probe beam intensity. All aberrations in thermal lens were taken into account. The model yields accurate values for absorption coefficient and thermal diffusivity of methylene blue aqueous solution. Furthermore, the optimized mode-mismatched version of this model when applied to pure water as a very low absorbent yields its absorption coefficient and thermal diffusivity values close to literature data. In contrast to traditional model, this model does not need to omit any term in its theory to fit the experimental data.

• 出版日期2013-10-7