Dual-scale turbulence in filamenting laser beams at high average power

摘要

We investigate the self-induced turbulence of high-repetition-rate laser filaments over a wide range of average powers (1mWto 100 W) and its sensitivity to external atmospheric turbulence. Although both externally imposed and self-generated types of turbulence can have comparablemagnitudes, they act on different temporal and spatial scales. While the former drives the shot-to-shot motion at the millisecond time scale, the latter acts on the 0.5-s scale. As a consequence, their effects are decoupled, preventing beam stabilization by the thermally induced low-density channel produced by the laser filaments.