Beam Distortion Effects upon focusing an ultrashort Petawatt Laser Pulse to greater than 10$^{22}$ W/cm$^{2}$

TL;DR

This paper investigates how beam distortions affect the focusing of ultrashort Petawatt laser pulses to intensities exceeding 10^22 W/cm^2, considering aberrations and alignment uncertainties.

Contribution

It provides an analysis of beam distortion effects on ultra-intense laser focusing, estimating peak intensities accounting for aberrations and alignment errors.

Findings

Estimated peak intensities are within acceptable error of measurements.

On-target peak intensities of ≥10^22 W/cm^2 are achievable with current setup.

Aberrations and pointing errors significantly influence the focused intensity.

Abstract

When an ultrashort laser pulse is tightly focused to a size approaching its central wavelength, the properties of the focused spot diverge from the diffraction limited case. Here we report on this change in behavior of a tightly focused Petawatt class laser beam by an F/1 off-axis paraboloid (OAP). Considering the effects of residual aberration, the spatial profile of the near field and pointing error, we estimate the deviation in peak intensities of the focused spot from the ideal case. We verify that the estimated peak intensity values are within an acceptable error range of the measured values. With the added uncertainties in target alignment, we extend the estimation to infer on-target peak intensities of $\geq$ 10$^{22}$ W/cm$^{2}$ for a target at the focal plane of this F/1 OAP.