@article{5562,
  author = {D. Oepts and R. J. Bakker and D. A. Jaroszynski and A. F. G. van der Meer and P. W. van Amersfoort},
  title = {Long-Range Coherence in a Short-Pulse Fel},
  abstract = {In the free electron laser for infrared experiments (FELIX), a radio-frequency linear accelerator is used to deliver electron micropulses with a duration of about 3 ps. The micropulses are repeated at a frequency of 1 GHz. The length of the optical cavity is 6 m, so that 40 independent optical micropulses are simultaneously circulating in the cavity. Almost complete coherence has been induced between the multiple pulses in FELIX by means of an intracavity Fox-Smith interferometer. A large fraction of the cavity modes is suppressed in this way, and the remaining lines have a relative width on the order of 1:10(6). The stability is in the same range. The gain and saturated power of the laser are almost unaffected. A single mode can in principle be selected from the output beam. This makes the resulting radiation useful for high-resolution spectroscopy applications. Coherence between successive micropulses has also been observed, quite unexpectedly, without the Fox-Smith arrangement.},
  year = {1993},
  journal = {Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipment},
  volume = {331},
  number = {1-3},
  pages = {42-47},
  month = {Jul 1},
  isbn = {0168-9002},
  doi = {10.1016/0168-9002(93)90010-f},
  language = {eng},
}