Obtaining monochromatic radiation from a free-electron laser by means of a system of coupled cavities (a mode selection method)

The idea of reducing the wavelength spread of the output from parametric free-electron lasers by means of a system of coupled cavities has been studied. Possibilities for optimizing the parameters of the system have also been studied. The intensity of the radiation from the laser can be kept essentially constant as the degree of monochromaticity is increased.