• Chinese Journal of Lasers
  • Vol. 48, Issue 12, 1201002 (2021)
Xiaomin Zhang1、*, Dongxia Hu1, Dangpeng Xu1, Jing Wang2, Xinbin Chen3, Jun Liu4, Wei Han1, Min Li1, and Mingzhong Li1
Author Affiliations
  • 1Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang, Sichuan 621900, China
  • 2Key Laboratory for Laser Plasmas, Ministry of Education, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
  • 3Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
  • 4Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, Sichuan 621900, China
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    DOI: 10.3788/CJL202148.1201002 Cite this Article
    Xiaomin Zhang, Dongxia Hu, Dangpeng Xu, Jing Wang, Xinbin Chen, Jun Liu, Wei Han, Min Li, Mingzhong Li. Physical Limitations of High-Power, High-Energy Lasers[J]. Chinese Journal of Lasers, 2021, 48(12): 1201002 Copy Citation Text show less


    Significance High-power lasers enable us to peer deeper into the outer frontiers of the physical world. Since the demonstration of the first pulsed laser in 1960, pushing the limits of accessible laser power has been one of the themes in optical engineering. In this article, we reviewed the progress in developing high-power solid-state lasers and discussed the design issues that determine the performance of these systems.

    Progress The more one works with a given technology, the more one becomes aware of its limitations—in the case of solid-state lasers, these are primarily the simultaneous availability of high peak and average powers, combined with excellent beam quality in space domain and pulse quality in time domain. In general, the output capability and beam quality of high-power solid-state lasers are essentially limited by five physical limitations categories—gain capability, beam transformation, thermal load, power load, and fluence load. Priority orders of these five limitations largely depend on the application scenario, operational mechanisms, and technical routes of specific laser facilities. For example, for high-power continuous lasers, the main challenge arises from the thermal load limit, while for high-power pulsed lasers, the critical challenge lies in the power load limit. Thus, detailed knowledge of the physics underlying these limitations and their interactions is crucial to the generation of high-quality, high-power lasers.

    We compiled some recent experimental and theoretical works on the understanding, avoidance, and breakthrough of these physical limitations, as well as relevant enabling developments for high-power solid-state lasers, including novel materials, geometries, and techniques. This paper consists of an introduction, five body sections, and a conclusion. Each section discusses the necessary ingredients for fighting against one of the five physical limitations. These are accompanied by numerous ideas and tips on how to improve the ef?ciency to make maximum use of pump energy.

    Conclusions and Prospects In conclusion, the core of breaking the gain capability limitation is fighting against the diverse “losses.” The chock point in breaking the limitation of beam and pulse quality is fighting against the diverse “noise” in all the domains of space, time, and spectrum. The key to overcome the limitation of thermal load is combating the thermal effects. Pushing the limit of power load prevents diverse nonlinear optical effects that accompany the propagation of high-power lasers. Furthermore, breaking the deadlock of the fluence load limit helps counteract the inevitable defects in optical elements. During the long struggle of physical limitations with these five categories, a series of novel laser materials, methods, optical techniques, techniques for optics processing, and geometries were correspondingly developed. In addition, theories on the dynamic properties of laser pumping and amplification, propagation, damage, and thermal control were deepened and consummated.

    We are now on the threshold to reach a new realm of high-power lasers—developing triple-high lasers with high-peak-power, high-energy (i.e., high-average-power), and high-repetition simultaneously. This is a new territory for laser engineering, which requires us to balance conflicting performance parameters. For example, the simultaneous availability of high-peak, average power (high-energy), presents a contradiction because increasing the peak power typically necessitates raising the laser bandwidth, causing an increase in the quantum defect and subsequent ef?ciency loss. This paper intends to be the beginning of a discussion, not the final word, to pave the way for “triple-high lasers.”