title: Generation of a self-chirped few-cycle optical pulse in a FEL oscillator.
abstract: We study the generation of a self-chirped optical pulse in a free-electron laser (FEL) oscillator. In a high-gain FEL oscillator, the frequency chirp is induced in the slippage region as a result of superradiant FEL resonance, and this time-frequency correlation evolves continuously into a few-cycle regime, if the optical cavity length is perfectly synchronized to the electron bunch interval. Numerical simulations based on the slowly evolving wave approximation and experimental results are presented.
authors.affiliation: Advanced Photon Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki, 319-1195 Japan. hajima@popsvr.jaeri.go.jp
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Hajima
authors.forename: Ryoji
authors.initials: R
authors.lastname: Nagai