Collinear photothermal deflection spectroscopy of liquid samples at varying temperature

The method of photothermal beam deflection was demonstrated for measuring the absorption spectrum of an aqueous Nd³⁺ solution at temperatures between 25°C and 90°C. Changes in the magnitude of the observed deflection can be correlated with the temperature dependence of both the absorptivity of the Nd³⁺ ions and the physical properties of the solvent, most notably the thermo-optic coefficient dn/dT.