激光驻波中运动电子的谐波自发辐射

Harmonics spontaneous emission due to electron motion in laser standing wave

采用单电子模型分析了电子在线极化激光驻波中的动力学及谐波自发辐射谱,数值计算了电子在驻波中的运动情况及辐射谱。结果表明:电子在波节和波腹处入射后,其辐射谱出现不同的特征;电子在波节处垂直磁场入射后,在洛伦兹力作用下快速振动并向前运动,其向后辐射的光谱发生红移,向前辐射的光谱发生蓝移,谱线出现展宽;当激光强度或者电子初始能量增大时,这些效应更加突出,以至于产生更高阶谐波,形成连续谱;而电子在波腹处以平行电场的方向入射后,仅在电场作用下作直线运动,其自发辐射谱线没有发生移动和展宽。

The dynamics and harmonics emission spectra due to electron motion in laser standing wave have been investigated considering a single electron model. The motion status of electron and harmonics radiation spectra are numerically analyzed. The electron with incident position at node and incident direction vertical to magnetic field oscillates rapidly under Lorentz force. The spectrum of radiation is redshifted for backward radiation and blueshifted for forward radiation, and thus spectral broadening is noticed. These effects are much more pronounced at higher laser intensity or initial electron energy, and even give rise to higher-order harmonics that eventually lead to a continuous spectrum. However, when the electron being incident at antinode and parallelly to electric field, it only moves linearly along electric field, and spectral shift and broadening vanish.