Physics

Deformable mirror

Lens (geology)

Chirped pulse amplification

CMOS

Laser

Focal length

Optics

Full width at half maximum

Streak camera

Adaptive optics

Laser beam quality

Parabolic reflector

Beam (structure)

Amplifier

Ultrashort pulse

Materials science

Laser beams

Optoelectronics

Optics Express

Double deformable mirrors (DMs) with different actuator densities are cascaded to optimize the wavefront aberrations to improve the focus intensity of the Shanghai super-intense ultrafast laser facility (SULF), which plans to generate 10 PW laser pulse. The beam aberrations near the focal spot are corrected from 0.556 um to 0.112 um in RMS by a 300-mm DM with a large stroke installed after the compressor. After then, it is further optimized to 0.041 um using a 130-mm DM with a high spatial resolution working after the main amplifier. The corrected beam is focused to 2.75 × 2.87 um2 at the full width at half maximum (FWHM) with an f/2.5 off-axis parabolic mirror (OAP), which contains approximately 27.69% energy. A peak intensity of 2 × 1022 W/cm2 is achieved at the output of 5.4 PW, and it could exceed 1023 W/cm2 in the SULF 10 PW laser facility using an f/1.8 OAP.

Improvement of the focusing ability by double deformable mirrors for 10-PW-level Ti: sapphire chirped pulse amplification laser system