Air-Lasing: High-Resolution Spectroscopy for Atmospheric Remote Sensing

Abstract

Air-lasing is a cavityless coherent radiation generated in free space from air constituents as the gain medium, featuring significant advantages such as high collimation, high coherence and high intensity. Benefited from the long-range filamentation of high-power ultrashort laser pulses propagating in air, the air-laser can be induced remotely which provides an ideal light source for atmospheric remote sensing and chemical specie-resolved detection. Thanks to the coherent atomic/molecular excitation process accompanying the generation of air laser, remote sensing based on air-laser has high spectral resolution and high detection sensitivity, which is recently proved to be a powerful tool for important applications such as trace molecule detection, greenhouse gas monitoring and industrial pollutant detection. In this short review, the physical mechanism of air laser is briefly introduced, and various applications of air laser remote sensing are reviewed emphatically, and the future research is prospected.