Stability of ultra-intense laser pulse propagation in a transversely perturbed plasma channel

Compared with the usual electron quiver for laser guidance at an intensity below 1020 W/cm2, the recent investigation revealed that the ions' response can guide the laser at an intensity exceeding 1022 W/cm2. Here, we study the stability of such an ultra-intense laser in the corresponding ion-responded channel with a transverse perturbation. The initial particle-in-cell (PIC) simulation investigation finds that the laser exhibits normal changes under a small-wavenumber perturbation but does display interesting and counterintuitive robustness under a large-wavenumber perturbation. To explain this behavior, we perform a linear stability analysis of the laser wave equation using the source-dependent expansion method. A detailed spectral analysis of the excited modes further elucidates the stark contrast between the two cases. In addition to these analyses, the influences of the perturbation wavenumber, amplitude, and the laser intensity on the stability are investigated in detail. The final PIC simulation further verifies the main findings and theoretical interpretations.