Measurements of the Size Variation of Optically Trapped Aerosol Water Droplets Using Cavity Enhanced Raman Spectroscopy (CERS)

Optical traps have numerous applications including the study of aerosol droplets. It has been observed that in a single beam optical trap, micro-meter sized aerosol droplets exhibit hysteric axial motion in the direction of beam propagation. Two meta-stable positions have been observed and it is thought that the cause of this motion between positions may be due to morphology dependent resonances (MDRs). For this to occur, thermal expansion of the droplet from a varying laser beam power must occur. Using Cavity Enhanced Raman Spectroscopy (CERS) we can investigate the size of the droplet as the position of the droplet and the laser power varied.