A method for aerosol fluorescence lifetime measurement based on Mie-fluorescence lidar

In this Letter, a remote sensing method for measuring the fluorescence lifetime of aerosols is proposed, which combines the Mie-fluorescence lifetime-scattering (MFLS) model, established based on Mie and fluorescence lidar theory, with the golden section search algorithm. The feasibility of this method was verified through numerical simulations, which demonstrate its ability to measure aerosol fluorescence lifetime by using nanosecond laser pulses. Experimental studies were conducted using a Mie and dual-wavelength fluorescence lidar system on four types of fluorescent substances in aerosol form. The experimental results demonstrate that the proposed method can robustly measure aerosol fluorescence lifetimes on the nanosecond scale, achieving a minimum relative standard deviation of approximately 5.5%. Furthermore, when fluorescence lifetimes are employed as input features for a machine-learning classifier (K-nearest neighbors), the four fluorescent substances were classified with an accuracy of 96.9%. This method offers new opportunities for fluorescence lidar applications in fluorescence lifetime measurement.