Paper 13139-1
Paper 13139-1
Spatial characteristics of air lasing inside femtosecond laser filaments (Invited Paper)
18 August 2024 • 8:30 AM - 8:55 AM PDT | Conv. Ctr. Room 11B
Abstract
Remote air lasing induced by femtosecond laser filamentation is expected as an effective way to produce a characteristic emission with high energy conversion efficiency and high signal to noise ratio. In this work, Spatial characteristics of air lasing inside femtosecond laser filaments has been studied. Non-uniform azimuthal distribution of N2+ fluorescence emitted from the femtosecond laser filament in air was discovered. The fluorescence is stronger when the detector is placed perpendicular or parallel to the laser polarization. The experimental results have been confirmed by the theoretical calculation that the azimuthal distribution of fluorescence is reproduced by the convolution of the transition of dipole and the molecular alignment in the strong laser field. Besides, our numerical simulation results show that Kerr effect plays a significant role in the spatial distributions and the far field divergence angles of air laser. The energy and far field divergence angle of air laser are strongly dependent on the external focus and the incident pump laser energy.
Presenter
Nankai Univ. (China)
Weiwei Liu received his Ph. D degree from Université Laval, Canada, in 2005, and jointed Nankai University in 2007 as a full professor. His research interest mainly focuses on the ultrafast laser optics, THz science and technology, and applications. He has already published more than 200 scientific papers in peer-reviewed journals with more than 10,000 citation, and H-index reaches 52 (Google Scholar). Prof. Liu has given more than 100 invited talks in international conferences worldwide. Now, he is serving as the director of Institute of modern optics, member of the standing committee of Chinese Optical Society and vice president of Optical Society of Tianjin, topic editor of Optics Lettes, Optica fellow, etc.