Wavefront Correction in Vacuum of SULF-1PW Laser Beamline

After the wavefront correction in vacuum with an adaptive optical system and the focusing with an f/56 off-axis parabolic mirror, near diffraction-limited focal spots with a size of 52 × 54 μm2 at full width at half maximum are achieved, and the enclosed energy inside this size is ~36.6%.

Consequently, the focused intensity of ~1.66×1019 W/cm2 can be achieved at 1 PW peak power. Moreover, we also examine the wavefront stability in air and vacuum respectively. From the statistical analysis of 1900 shots successive laser pulses at 1 Hz, we identify the wavefront fluctuation resulted from air turbulence and the better correction capacity in vacuum.