Fast laser field reconstruction method based on a Gerchberg–Saxton algorithm with mode decomposition

Abstract

Knowledge of the electric field of femtosecond, high intensity laser pulses is of paramount importance to study the interaction of this class of lasers with matter. A hybrid method to reconstruct the laser field from fluence measurements in the transverse plane at multiple positions along the propagation axis is presented, combining a Hermite–Gauss mode decomposition (MD) and elements of the Gerchberg–Saxton algorithm (GSA). The proposed GSA-MD takes into account the pointing instabilities of high intensity laser systems by tuning the centers of the HG modes. Furthermore, it quickly builds a field description by progressively increasing the number of modes and thus the accuracy of the field reconstruction. The results of field reconstruction using the GSA-MD are shown to be in excellent agreement with experimental measurements from two different high peak power laser facilities.

Stabilization and correction of aberrated laser beams via plasma channelling

“…3 ), one has to define the initial intensity and wavefront error distribution in the near field (for example, using Zernike formalism). Either an experimental case (for instance measured with a camera and a wavefront sensor 8 , or numerically reconstructed 11 , 12 , 34 ) or a theoretical case (for instance a top-hat beam with a wavefront error of /10 for astigmatism) can be used. Then, for implementing and reproducing the real beam used in our simulation, it is required to extract at least = 500 slices (with a resolution of for the transverse field) from Fresnel, corresponding to the different positions of the PIC windows, separated by 50 nm.…”

“…3 ), one has to define the initial intensity and wavefront error distribution in the near field (for example, using Zernike formalism). Either an experimental case (for instance measured with a camera and a wavefront sensor 8 , or numerically reconstructed 11 , 12 , 34 ) or a theoretical case (for instance a top-hat beam with a wavefront error of /10 for astigmatism) can be used.…”