On 18 December 2024, Jonas B. Ohland gave an online presentation on one of the technologies behind the THRILL project in his Laserlab-Europe talk “From Telescopes to Fusion Powerplants: Real-Time Adaptive Optics for High-Power Lasers”.

Watch the recording: https://www.youtube.com/watch?v=xAj0Gc22Hpk&t=4s

Summary: The Apollon Real-Time Adaptive Optics (ARTAO) system addresses air turbulence-induced Strehl ratio fluctuations in Apollon, the 10 PW Ti:Sapphire laser system in France. With a 50 m multi-pass amplifier and a 140 mm beam diameter, turbulence previously caused significant beam quality instability. To resolve this, the open-source AO platform CACAO, originally developed for the Subaru Observatory, was adapted for real-time beam stabilization using a continuous pilot beam. This marks a pioneering application of astronomical AO technology in ultra-high-intensity lasers.

Supported by the EC funded THRILL project under its wavefront stabilization task, ARTAO demonstrates a stability sufficient to achieve an on-shot Strehl ratio above 0.96 by evaluating 2.6 thousand wavefronts per second and controlling a deformable mirror at 1.3 kHz.

This technology has great potential for future applications: in Inertial Confinement Fusion (ICF) powerplants, real-time AO will be indispensable for operating hundreds of laser beamlines at 10 Hz, delivering MJ-scale pulses with minimal aberrations. By integrating AO into Adaptive Laser Architecture (ALA), these systems can overcome thermal challenges and meet the demands of fusion energy production.

This presentation will detail ARTAO’s development, initial results, and its potential role in the future of high-energy laser systems.