One of the latest cover paper published in JPCL  presents our study on the spatial distribution of nitrogen gas fluorescence during femtosecond laser filamentation. In this work, 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. The results would provide new insight into laser-molecule interactions during filamentation, which are important in practice for remote-sensing using filamentation. 

      This paper is a collorative result between Prof. Weiwei Liu and Prof. ZhinanZeng from SIOM, and is sponsored by fundings such as the National key research and development program.

  （ The paper can be downloaded from https://pubs.acs.org/doi/10.1021/acs.jpclett.9b03025）