关键词: 亚密度等离子体, 冷等离子体, 小功率激光, 碰撞吸收

Abstract:

The laser energy absorption in underdense cold plasma, where the electron density is much lower than the critical value corresponding to the incident low power laser, is very different from that of the hot plasma with high electron concentration. In this plasma, the collision frequency between electrons and neutral particles is dominant and much greater than that between electrons and ions. This results in the change of the character of collision absorption, and therefore the collision absorption of low power laser in the band of visual light and infrared is negligible because of the low electron density and the low collision frequency. However, the effects of abnormal absorption mechanism need to be studied deeply.

Key words: Underdense plasma, Cold plasma, Low power laser, Collision absorption