Influence of Spatio-Temporal Couplings on Focused Optical Vortices

Abstract

Ultra-intense laser pulses with helical phases are of interest in laser-driven charged particle acceleration and related experiments with extreme light. However, such optical vortices can be affected by the presence of residual spatial-temporal couplings. Their field distributions after propagating in free-space and in the focal plane of an ideal focusing mirror were assessed through numerical modeling, based on the Gaussian decomposition method for a 25 fs pulse with a Supergaussian spatial profile. The wash-out of the central hole in the doughnut-shaped profile in the focal plane corresponds to the rotation of the phase discontinuity.

Keywords

• high-power lasers
• ultra-short pulses
• helical phase
• optical vortex
• spatio-temporal couplings
• laser pulse propagation