本文根据单粒子模型阐述了自由电子激光放大器的工作原理,通过将电子运动方程线性化导出了小信号增益。结果表明,当电子束有合适的初速分布,周期静磁场和入射电磁波有确定的相位关系,并且满足电子与波的同步条件和电子回旋谐振条件时,电子能持续地和最有效地将能量交给入射电磁波,从而实现激光放大。

The single-partiol? model is used to explain the working principle of free-eloofcroa laser amplifier. After linearizing the motion equation of electron,we got the small-signal gain. The results show that the electron beam has suitable initial velocity distribution, the initial phases of the static periodic magnetic field and incidont oleotromagnetio wave have definite relation, the syohronization requirement between electrons and wave and the cyclotron rosonace oondition are satisfied. The electrons can transfer their energy to the wave efficiently and oonstanily so that laser amplitioation can be achievod.