自由电子激光(FEL)是以电子加速器产生的高能相对论电子束为增益介质的一种新型激光。早在1933年Kapitza与狄拉克就研究过相对论电子束与电磁波场的相互作用,为FEL理论的建立奠定了基础。而这方面的大量工作则始于70年代初。1971年Madey在研究相对论电子束通过周 Free Electron Laser (FEL) is a new kind of laser that uses the high energy relativistic electron beam generated by the electron accelerator as the gain medium. As early as 1933, Kapitza and Dirac studied the interaction between the electron beam and the electromagnetic wave field, which laid the foundation for the establishment of FEL theory. Much work in this area began in the early 1970s. In 1971 Madey studied the theory of relativity electron beam through the weeks