Harmonic Generation in the Novosibirsk Terahertz Free Electron Laser

At the present time, the radiation of the main first harmonic of the Novosibirsk terahertz free electron laser (FEL) lies in the range of 120-230 mum with power level of up to 400 W. The radiation of second and third harmonics was experimentally found in the FEL. This high harmonic FEL radiation extends its spectral range by a factor of 3. Rather high second harmonic radiation unusual for typical FEL allows uninterrupted radiation in the range of 40-230 mum.