2023/04/26 by Shing Yiu Fu, Fu, Shing Yiu, Kareem J. Garriga Francis +7
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #FOS: Physical sciences #Laser Design and Applications #Laser-Matter Interactions and Applications #Optics (physics.optics)
paper · pdf · doi:10.48550/arxiv.2304.13264
openalex publication_date 2023/04/26 · openalex created_date 2023/04/28 · openalex updated_date 2026/07/28
We report a systematic investigation into the processes behind a near hundredfold enhanced second harmonic wave generated from a laser-induced air plasma, by examining the temporal dynamics of the frequency conversion processes, and the polarization of the emitted second harmonic beam. Contrary to typical nonlinear optical processes, the enhanced second harmonic generation efficiency is only observed within a sub-picosecond time window and found to be nearly constant across fundamental pulse durations spanning from 0.1 ps to over 2 ps. We further demonstrate that with the adopted orthogonal pump-probe configuration, the polarization of second harmonic field exhibits a complex dependence on the polarization of both input fundamental beams, contrasting with most of the previous experiments with a single-beam geometry.