Irradiance and laser wavelength dependence of plasma spectra from single levitated aerosol droplets.

Plasma spectra initiated on single, optically levitated, micron-sized droplets of a glycerine-saturated brine solution are presented. The temporal development of the droplet plasma is monitored by observing neutral and once-ionized carbon and neutral sodium emission, and that of the air plasma by once-ionized nitrogen emission. The dependence of the plasma on laser parameters, such as wavelength and irradiance, is discussed.