Observation of suppression of morphology-dependent resonances in singly levitated micrometer-sized droplets

Suppression of morphology-dependent resonances of the light elastically scattered by a laser-illuminated, micrometer-sized droplet is reported. A single nonabsorbing droplet is levitated by using an electrodynamic quadrupole trap, and the scattered light is monitored as the droplet slowly evaporates. The size of the droplet is approximated by using the instability characteristics of the electrodynamic trap. To determine the refractive index and droplet radius precisely, the experimental scattering curve is fitted to a scattering curve that is generated from Mie theoretical calculations. The procedure is then repeated for absorbing droplets. The quality factor Q of each experimental resonance is determined and used to quantify the suppression effect. A dramatic suppression of narrow resonances occurs with increased absorption, whereas little or no effect is seen in moderate to broad resonances.