Development of a Free-Electron Laser in the Terahertz Region

Isoyama; Goro

Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan (isoyama@sanken.osaka-u.ac.jp) 

We have been developing a free-electron laser (FEL) in the far-infrared or terahertz (THz) region for higher intensity and stability, using the L-band (1.3 GHz) electron linear accelerator (linac) at the Institute of Scientific and Industrial Research (ISIR), Osaka University. The FEL was progressively upgraded, and the maximum energy of micropulses, which form an FEL macropluse of a duration of some microseconds, reached 260 μJ at a wavelength around 65 μm or a frequency around 4.6 THz, which is an order of magnitude higher than micropulse energies obtained in other FELs in this wavelength or frequency range. Experiments have begun using high-intensity narrow-band terahertz radiation from the FEL. This paper summarized the progress of the FEL and its application experiments.

Keywords: Free Electron Laser (FEL), Electron, Linear Accelerator (Linac), Terahertz (THz), Far-Infrared