Sensitive Detection of Phase Separation with Femtosecond Thermal Lens Spectroscopy

Femtosecond Thermal Lens Spectroscopy (FTLS) has been developed to a level of sensitivity that can have molecule specific response due to convection as demonstrated experimentally and theoretically. Within this framework, we show here that it is possible to use this technique for sensitive detection of liquid versus gas phase. Experimental demonstration is made with a single beam FTLS experiment of traces of iodine in pentane mixture in liquid versus its vapor phase.