【摘要】 为了更完善地研究强的短脉冲激光在次临界密度冷等离子体中传播时的自聚焦现象,采用了包括洛伦兹项和牵连项的更为完整的有质动力形式。通过理论推导可知,牵连项的加入对自聚焦有一定的影响,使得产生自聚焦的非线性效应更强。同时也考虑到在激光达到一定强度的时候,需要计入相对论效应。结果表明,相对论效应的计入虽然增强了体系的非线性度,但与长脉冲激光中的相对论自聚焦效应不一样的是,它减弱了非线性效应对自聚焦的影响。更多还原

【Abstract】 In order to study self-focusing phenomenon of an intense short laser beam propagating in cold, underdense plasma,the more complete ponderomotive force of laser beam propagating with implicate term and Lorenz term was used. Calculation show that the implicate term has stronger nonlinear effect on self-focusing. Meanwhile the relativistic effect should be considered when laser pulse becomes strong enough. Although the consideration of relativistic effect makes the system nonlinearity larger, it could decrease the nonlinear effect on self-focusing. This is different from the relativistic self-focusing of long laser pulse.更多还原