相对论激光等离子体中的电磁孤波

Electromagnetic Soliton in Relativistic Laser-Plasma

激光在等离子体中传播时发生调制相互作用,导致产生调制不稳定性。随着不稳定性的非线性演化,在一维情况下将形成电磁孤波。利用电磁波在相对论等离子体中的非线性色散关系以及Karpman方程,分析强激光在相对论性等离子体中的调制不稳定性,获得一般情况下调制不稳定的增长率与扰动态波数之间的函数关系,同时得到一维情况下的电磁孤波。分析表明,随着激光功率的增大,相对论性强激光与等离子体发生相互作用产生的调制不稳定性的时间增长率峰值显著增大,但是电磁孤波的半宽明显减小。

When an incident laser beam propagates in plasma, there is modulation interaction and the modulation instability occurs. With the nonlinear development of the instability, it would lead to the formation of electromagnetic soliton. Based on the nonlinear dispersion relation of electromagnetic wave in relativistic plasma and Karpman equation, the modulation instability of intense laser beam in relativistic plasma is studied. The function of temporal growth rate and perturbation wave number is generally obtained and the envelope soliton is derived. With the power of laser pulse increasing, the temporal growth rate of the modulation instability for the relativistic intense laser beam will be in- creased obviously, but the halfwidth of the soliton wave is reduced.