Thermal lens effect induced by laser beam in tetracarbonyl(2,2′-bipyridyl)chromium(0) complex

The thermal lens effect of Tetracarbonyl(2,2 '-bipyridyl)chromium(0) complex (TCPC) solution was investigated using the mode-match dual beam z-scan technique. The thermal lens (TL) parameters of the TCPC solutions, such as: the convective velocity, thermal diffusivity, thermo-optic coefficient, on-axis phase shift, thermal diffusion time and Peclet number, were extracted using thermal lens theoretical model. It was found that with the increasing input pump laser powers, the thermal diffusion time and Peclet number decreased, while the on-axis phase shift increased as a result of the laser powers increase. As two wavelengths laser, lambda(e)=532 nm and lambda(e)=635 nm were used for excitation powers, the new results have shown how the wavelength effects molecular heat convection in the (TCPC) solution.