  Femtosecond laser filament-induced plasma spectroscopy (FIPS) demonstrates
great potentials in the remote sensing for identifying atmospheric pollutant
molecules. Due to the widespread aerosols in atmosphere, the remote detection
based on FIPS would be affected from both the excitation and the propagation of
fingerprint fluorescence, which still remain elusive. Here the physical model
of filament-induced aerosol fluorescence is established to reveal the combined
effect of Mie scattering and amplification spontaneous emission, which is then
proved by the experimental results, the dependence of the backward fluorescence
on the interaction length between filament and aerosols. These findings provide
an insight into the complicated aerosol effect in the overall physical process
of FIPS including propagation, excitation and emission, paving the way to its
practical application in atmospheric remote sensing.
