Breaking symmetry in propagation of radially and azimuthally polarized high power laser pulses in underdense plasma

Abstract

Propagation of relativistically intense azimuthally or radially polarized laser pulses (RPP) is demonstrated, via 3D particle-in-cell simulations, to be unstable in uniform underdense plasma. Strong breaking of the pulse symmetry occurs for RPP with power exceeding the critical one for self-focusing in transversely uniform plasma with an increment, Γ, close to the well-known Rayleigh-Taylor-like instability depending on the acceleration, α, and the modulated density gradient length, L, as Γ≈(α/L)1/2. In deeper plasma channels, the instability vanishes. Electron self-injection in the pulse wake and resulting acceleration is explored.