Fourier Spectroscopy of Radiation of Novosibirsk Terahertz Free Electron Laser

We have investigated various spectral parameters of Novosibirsk terahertz free electron laser (FEL) in different regimes by Bruker vacuum Fourier spectrometer IFS-66v. In addition to routine wavelength measurement and calibration we studied also radiation of harmonics [1] and detailed form of FEL spectrums. Such interesting phenomena as sideband instability [2] and two wavelength generation have been demonstrated very distinctly in our FEL.