Mode-locked super-radiant free-electron laser oscillator

Y. Pinhasi, A. Gover

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Evolution of the time domain fields and the spectral power of super-radiant radiation in a free-electron laser oscillator (e-beam pulses shorter than a wavelength) are investigated. We consider a finite train of N short bunches of electrons propagating through the undulator. The coherence of the synchrotron radiation emitted from the bunched beam grows with the number N of the e-beam pulses entering the interaction region. When N grows to infinity, the radiation becomes perfectly coherent at all harmonic frequencies of the pulse injection (bunching) frequency. When the super-radiant emission takes place inside a resonator, the coherence of the emitted radiation is enhanced. Under the condition of mode-locking, the fields add in phase and the spectral energy distribution becomes narrow. When the finesse F of the resonator is small F < N, the spectral width of the out-coupled radiation emitted from the resonator is limited by N, and in the opposite case F > N, it will be limited by F. If the number of pulses N grows to infinity, the out-coupled radiation reaches a steady state of perfect coherence with reduced harmonic contents (determined by the Finesse of the resonator). There is no threshold for emission of this kind of coherent radiation.

Original languageEnglish
Pages (from-to)86-89
Number of pages4
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Issue number1-3
StatePublished - 11 Apr 1995
Externally publishedYes


Dive into the research topics of 'Mode-locked super-radiant free-electron laser oscillator'. Together they form a unique fingerprint.

Cite this