研究目的
To examine the impact of non-linear longitudinal phase distortions on the spectral bandwidth in echo seeded free electron lasers (FELs) and to extend the existing theory for echo-enabled harmonic generation (EEHG) to include finite laser pulse durations.
研究成果
The paper concludes that the time-bandwidth product (TBP) and the bandwidth increase by no more than √2 from their transform-limited values when the bandwidth is minimized. It also shows that by proper optimization, the TBP and the bandwidth can be no more than √2 times the transform-limit if the phase distortions are described by a single polynomial term.
研究不足
The study assumes that the system is far from the minimum pulse duration limit and utilizes the weakly-folding approximation which assumes that the energy structures are small enough so that they do not lead to large changes in the phase space distribution after the first chicane.
