The advantages of free electron lasers over traditional lasers

The operating mechanism of the free electron laser is not affected by the atomic and molecular media, so the free electron itself does not have a lifespan problem. The average power reaches several kilowatts, and the high average power of several megawatts may also be reached, and the peak power reaches gigawatts. The efficiency of 10u0026mu;m wavelength laser is above 20~50%, and the efficiency can be improved by the recovery of electron beam energy. Free electron lasers can work in the entire electromagnetic spectrum and can oscillate in the short wavelength range (vacuum ultraviolet, soft X-ray) that ordinary lasers cannot oscillate. Since free electron lasers have no intermediate energy conversion links, their efficiency is very high. (1) Traditional lasers are realized by light emission generated by the transition between energy levels determined by electrons in atoms or molecules, while free electron lasers have no inherent energy level limitations, and their output wavelengths are continuously adjustable in a wide range. .　　 (2) The most attractive part of free electron lasers is that they can generate very high power. In recent decades, it has developed very rapidly and has become an eye-catching research direction in modern physics.　　 (3) Due to the decay of the performance of the working material in the general laser, the working life is short. Free electron lasers will become an important light source in this century. The beam divergence angle of the free electron laser can reach the diffraction limit.　　 free electron laser is a completely new type of coherent light source, some of its characteristics are unmatched by other coherent light sources. In addition, the free electron laser also has a narrow time structure and output frequency band, stable operation and good repeatability. At present, most application-related free electron lasers work in the near-infrared, mid-infrared, and near-ultraviolet spectral bands. Free-electron lasers are also expected to become an important tunable radiation source for far-infrared and sub-millimeter wave radiation.　　 (4) The optical spectrum of free electron lasers is relatively pure, which avoids effects such as medium absorption and self-focusing caused by the active medium in traditional lasers, and therefore helps to improve the quality of the beam. After briefly describing the principle of free electron lasers, this article introduces the development and applications of free electron lasers. (The above is edited and reproduced by Wuhan High Energy Laser Cutting Machine, please indicate the source!)