Coupled air lasing gain and Mie scattering loss: aerosol effect in filament-induced plasma spectroscopy

TL;DR

This paper investigates how aerosols affect femtosecond laser filament-induced plasma spectroscopy (FIPS) by analyzing the interplay of Mie scattering and gain, providing insights for atmospheric remote sensing applications.

Contribution

It introduces a physical model of aerosol effects in FIPS, combining Mie scattering and spontaneous emission, supported by experimental validation.

Findings

Backward fluorescence depends on filament-aerosol interaction length.

Aerosol presence influences excitation and emission processes in FIPS.

The model enhances understanding of aerosol impacts on remote sensing accuracy.

Abstract

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.