Development of Free Electron Lasers in the VUV-IR Range Using a Single Compact Storage Ring NIJI-IV and Their Application to the Surface Science

Storage ring free electron lasers (FELs) with optical cavities have substantial advantages, such as narrow line width, fine lateral mode distribution, good coherence and easy synchronism with the synchrotron radiation from dipole magnets and other insertion devices. These features, in addition to their wide wavelength tunability, enable them to be excellent tools for both pump and probe in the photon-induced phenomena. At AIST, FELs are being developed at wavelengths ranging from the infrared (IR) down to the vacuum ultraviolet (VUV), based on a single compact storage ring NIJI-IV. FEL application experiment was also started in the surface science field. Here, we report recent progress in the research and development on the NIJI- IV FEL system.