Influence of a step-tapered undulator field on the optical pulse shape of a far-infrared free electron laser
- FOM Inst. for Plasma Physics Rijnhuizen, Nieuwegein (Netherlands)
- Commissariat a l`Energie Atomique, Bruyeres-le-Chatel (France). Service de Physique et Techniques Nucleaires
The optical output of the free-electron laser for infrared experiments (FELIX), which operates in the regime of strong slippage, consists of picosecond pulses. Depending on the amount of cavity desynchronization, the optical pulse can develop substantial structure in the form of multiple subpulses. The authors present second-order autocorrelation measurements of the subpulses at several far-infrared wavelengths while applying a step-taper in the undulator field. The operation with a step-tapered undulator prevents the electrons from reabsorbing the optical field energy, leading to a smooth optical pulse. For different settings of the undulator the measured pulse shape and corresponding power spectrum are discussed. It is possible without decreasing the small-signal gain to produce a smooth high-power optical pulse during the whole saturated part of the machine pulse in an FEL oscillator with a reverse-step tapered undulator.
- OSTI ID:
- 253677
- Journal Information:
- IEEE Journal of Quantum Electronics, Vol. 32, Issue 6; Other Information: PBD: Jun 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Simulations of the TJNAF FEL with tapered and inversely tapered undulators
A tapered undulator experiment at the ELBE far infrared hybrid-resonator oscillator free electron laser