自由电子激光是相对论电子束在外场的激励下经受激放大产生的相干光源。由于它具有频率连续可调、功率大、效率高、光束质量好等优点,自70年代中期问世以来就受到了世界各国的重视。近20年来,经各国科学家的共同努力,在探索新的物理机制和发展新的技术途径、开辟新的应用项目等方面,都取得了令人瞩目的进展。我国自由电子激光的研究,始于80年代中期。经过近10年的努力,一批研究项目已经在各个研究所和大学相继获得成功,有些项目已在亚洲处于领先水平, Free electron lasers are relativistic electron beams excited by the excitation of the external field generated by coherent light source. Because of its advantages of continuous adjustable frequency, high power, high efficiency and good beam quality, it has been valued by all countries in the world since it was introduced in the mid-1970s. In the past 20 years, remarkable achievements have been made in the joint efforts of scientists from all over the world, in exploring new physical mechanisms, in developing new technological approaches and in opening up new application projects. China's free electron laser research, began in the mid-1980s. After nearly 10 years of hard work, a number of research projects have succeeded in various institutes and universities successively. Some of them have taken the lead in Asia,