Broadband Dispersive-Wave Emission Coupled with Two-Stage Soliton Self-Compression in Gas-Filled Anti-Resonant Hollow-Core Fibers
preprintposted on 2023-08-02, 16:00 authored by Jinyu Pan, Zhiyuan Huang, Yifei Chen, Fei Yu, Dakun Wu, Tiandao Chen, Donghan Liu, Yue Yu, Xin Jiang, Meng Pang, Yuxin Leng, Ruxin Li
We studied the underlying mechanism of broadband dispersive-wave emission within a resonance band of gas-filled anti-resonant hollow-core fiber. Both theoretical and experimental results unveiled that the high-order soliton, launched into the hollow-core fiber, experienced two stages of pulse compression, resulting in a multi-peak structure of the dispersive-wave spectrum. Over the first-stage pulse compression, a sharp increase of the pulse peak power triggered the first time of dispersion-wave emission, and simultaneously caused ionization of the noble gas filled in the fiber core. Strong soliton-plasma interactions led to blue shifting of the pump pulse, and the blue-shifted pulse experienced a decreasing dispersion value in the fiber waveguide, resulting in an increase of its soliton order. Then, the second-stage pulse compression due to the high-order soliton effect triggered the second time of dispersive-wave emission at a phase-matched frequency slightly lower than that in the first stage. Multi-peak spectra of the output dispersive-waves and their formation dynamics were clearly observed in our experiments, which can be understood using a delicate coupling mechanism among three nonlinear effects including high-order-soliton compression, soliton-plasma interaction and phase-matched dispersive-wave emission. The output broadband dispersive-wave could be potentially compressed to sub-30 fs duration using precise chirp-compensation technique.