The self-focusing/defocusing of Hermite-sinh-Gaussian (HshG) laser beam in underdense inhomogeneous plasmas is studied by using higher-order approximation theory. It is found that Hermite mode index and the fluctuation of the periodic plasma density have a significant effect on the dielectric constant and laser beam self-focusing/self-defocusing. With the increase of mode index, the high-order HshG laser beam is beneficial to suppress self-focusing and enhance self-defocusing. In addition, the effects of decentered parameters, beam intensity, and plasma non-uniformity on self-focusing/self-defocusing are discussed.

中文翻译：

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Hermite-Sinh-Gaussian 激光束在低密度非均匀等离子体中的自聚焦/散焦

利用高阶逼近理论研究了Hermite-sinh-Gaussian (HshG)激光束在低密度非均匀等离子体中的自聚焦/散焦。发现Hermite模式指数和周期性等离子体密度的波动对介电常数和激光束自聚焦/自散焦有显着影响。随着模式指数的增加，高阶HshG激光束有利于抑制自聚焦和增强自散焦。此外，还讨论了偏心参数、光束强度和等离子体不均匀性对自聚焦/自散焦的影响。