RELATIVISTIC EVEN-ORDER HARMONICS GENERATED IN UNDERDENSE PLASMA
欠稠密等离子体中诱发的偶次相对论谐波

In the self-generated magnetic field produced by ultra-intense laser-plasma interaction or background magnetic field, even relativistic harmonics is excited by the ultra-intense laser propagating in underdense plasma which is magnetized by the self-generated magnetic field or backgroud magnetic field. In this paper, the second harmonics and its parameters are investigated.