RADIAL PROFILING OF MICRODROPLETS USING CAVITY-ENHANCED RAMAN-SPECTROSCOPY

The composition of 7.7-mu m-radius methanol-water droplets was radiall y resolved by cavity-enhanced Raman spectroscopy. Optical cavity modes , encompassing well-defined radial zones within each droplet, were seq uentially excited by a 514.5-nm laser beam to generate spontaneous Ram an scattered light. The cavity-enhanced Raman spectral peaks gave info rmation as to the identity and amount of species present. The measured radial and time dependence of the methanol concentration agreed with a diffusion-limited evaporation mode.