Characterization of focal field formed by a large numerical aperture paraboloidal mirror and generation of ultra-high intensity (10 22 W/cm 2 )

Abstract

We describe a method to measure the aberrations of a high numerical aperture off-axis paraboloid and correct for the aberrations using adaptive optics. It is then shown that the characterized aberrations can be used to accurately calculate the electromagnetic field at the focus using the Stratton–Chu vector diffraction theory. Using this methodology, an intensity of 7×10 21 W/cm 2 was demonstrated by focusing a 45-TW laser beam with an f /0.6, 90 ∘ off-axis paraboloid after correcting the aberrations of the paraboloid and the low-energy reference beam. The intensity can be further increased to 1×10 22 W/cm 2 by including in the correction algorithm the wavefront difference between the reference beam and the high-energy beam.