HotLoop Optimization of Petawatt Laser Focal Spot via a Twin-Focus Scheme
Abstract
Achieving diffraction-limited focusing of high-power laser pulses to generate ultra-high intensities is crucial for developing compact laser-driven particle accelerators and exploring strong-field quantum electrodynamics. However, accurately diagnosing and optimizing the focal spots of petawatt (PW) laser pulses remains a significant challenge. In this work, we present an experimental methodology utilizing a twin-focus scheme to precisely characterize the intensity distribution and wavefront of focused PW femtosecond laser pulses, and employ it to elucidate their power-dependent evolution. Furthermore, we optimized the focal spots at full power via our in-situ wavefront correction method termed ``HotLoop', achieving a Strehl ratio of 0.80 for 1 PW laser pulses. Consequently, the cutoff proton energies in laser proton acceleration experiments were significantly enhanced. The success of this approach underscores the necessity of in-situ high-energy wavefront correction for ultra-high intensity laser-matter interactions.
Keywords
Cite
@article{arxiv.2605.20647,
title = {HotLoop Optimization of Petawatt Laser Focal Spot via a Twin-Focus Scheme},
author = {Qingfan Wu and Ying Gao and Minjian Wu and Jiarui Zhao and Shiyou Chen and Tianhao Liang and Haoran Chen and Tan Song and Zhongshuai Zhang and Zhangyi Wu and Shirui Xu and Ziyang Peng and Tianqi Xu and Zhuo Pan and Yujia Zhang and Qihang Han and Ke Chen and Chenghao Hua and Pengcheng Fan and Yuntian Xie and Yifei Shen and Shengxuan Xu and Liyong Ma and Yixing Geng and Chen Lin and Yanying Zhao and Xueqing Yan and Wenjun Ma},
journal= {arXiv preprint arXiv:2605.20647},
year = {2026}
}
Comments
Accepted by Matter and Radiation at Extremes (MRE)