Suppression of scattering resonances in inhomogeneous microdroplets

Resonance structure in elastic scattering was measured for evaporating micrometer-sized glycerol droplets suspended in an electrodynamic trap. Seeding the droplets with polystyrene latex particles having a diameter of 30 nm ≤ d ≤ 105 nm broadens and attenuates the highest Q (with bare Q ≈ 103−105) resonances, where Q is defined as the ratio of the energy stored to the energy lost from a cavity per cycle. Regardless of whether resonance conditions are satisfied, the presence of latex particles causes fluctuations in the scattering with an amplitude of up to ≈30% of the total signal. Model calculations suggest that the fluctuations may be due at least partially to agglomerated latex particles passing through hot-spot regions within the droplet.