Polarization phenomena in diffraction radiation generators - Free-electron lasers

The relationship between diffraction radiation polarization and the magnitude of the electron-focusing permanent magnetic field in a diffraction radiation generator (a type of free-electron laser) has been investigated experimentally using a quasioptic resonance polarimeter. Experiments were carried out in the millimeter range at 80 GHz. It is found that the polarization plane of the diffraction radiation generator rotates with changes in the magnitude of the focusing magnetic field due to the fact that one component of the electric field changes faster than the other.