Control of chaos in free-electron laser

A theoretical investigation is made of a possibility for the control of the chaotic behavior of the free-electron laser upon imposing the sinusoidally varying perturbations to the electric current or the electron beam. Numerical simulation of the one-dimensional time-dependent model is performed for the energy and the synchrotron phase of the electrons and for the electric field of the laser. It is found that aperiodic nature of the laser output may become periodic and the spectral property is improved.