Thermal lens effect in a binary liquid mixture: A new effect

Abstract

We present data showing that the thermal lens effect in a binary liquid mixture is noticeably larger than in its two pure constituents. The anomalous effect observed in the mixture is interpreted as a consequence of the buildup of thermally induced concentration gradients (Soret effect). We suggest that the thermal lens technique could be exploited for determining the thermal diffusion ratio k_T in binary liquid mixtures.