An extension and new application of the Laser Induced Fluorescence (LIF) is here developed for supercooled droplet characterization (temperature and solidification). In a first step, the choice of fluorescent dyes is determined by the study of fluorescent spectra at different temperatures. A couple of two fluorescent dyes has been identified allowing a temperature measurement. The water (with both dyes) was then calibrated in temperature using a suspended droplet up to a temperature of −17°í µí° and a sensitivity of 2.56%/°í µí° was obtained. The measurement technique is then used to determine the droplet temperature in free fall in a cold environment. An experimental setup consisting of a column with a height of 79í µí±í µí±š whose internal temperature can be controlled up to a temperature of −54°í µí° is used. Two configurations of drops were tested: individual drops generated by a syringe pump and a mono-sized droplet chain. In parallel, numerical simulations were carried out for both configurations (taking into account the internal circulation of the liquid within the drops and the drop-drop interactions) possible to set up a second fluorescence ratio that is very sensitive to phase change. This second ratio was tested on a suspended droplet and in an experimental setup that allows a following of the phase change more precisely. It appears an almost proportional evolution between the evolution of the ratio and the evolution of ice in the water. Finally, measurements of Raman spectroscopy and MRI have been performed in order to confirm that LIF is a relevant technique to detect and estimate the ice fraction.