Optical Klystrons and High-Gain Harmonic Generation

  • H. P. Freund
  • T. M. AntonsenJr.


Optical klystrons have been in use for decades, and the first use was in an ultraviolet free-electron laser oscillator. An optical klystron (OK) is composed of a modulator wiggler that imposes a velocity modulation on the electrons followed by a magnetic dispersive section that enhances the modulation prior to injection into a radiator wiggler that takes the interaction with the modulation-enhanced electrons to saturation. The magnetic dispersive element is, typically, a three- or four-dipole chicane. The radiator can be tuned to the fundamental or a harmonic of the modulator, in which case the interaction is referred to as high-gain harmonic generation (HGHG). In this chapter, we discuss these concepts and simulations of representative configurations.


Optical klystron OK High-gain harmonic generation HGHG Modulator Radiator Magnetic chicane Multistage optical klystron MSOK Harmonic cascade 


  1. 1.
    G.N. Kuliapanov, V.N. Litvinenko, I.V. Panaev, V.M. Popik, A.N. Skrinsky, A.S. Sokolov, N.A. Vinokurov, The VEPP-3 storage ring optical klystron: lasing in the visible and ultraviolet regions. Nucl. Instrum. Meth. A296, 1 (1990)CrossRefGoogle Scholar
  2. 2.
    L.H. Yu, M. Babzien, I. Ben-Zvi, L.F. DiMauro, A. Doyuran, W. Graves, E. Johnson, S. Krinsky, R. Malone, I. Pogorelsky, J. Skaritka, G. Rakowsky, L. Solomon, X.J. Wang, M. Woodle, V. Yakimenko, S.G. Biedron, J.N. Galayda, E. Gluskin, J. Jagger, V. Sajaev, I. Vasserman, High-gain harmonic-generation free-electron laser. Science 289, 932 (2000)CrossRefGoogle Scholar
  3. 3.
    A. Doyuran, M. Babzien, T. Shaftan, L.H. Yu, L.F. Dimauro, I. Ben-Zvi, S.G. Biedron, W. Graves, E. Johnson, S. Krinsky, R. Malone, I. Pogorelsky, J. Skaritka, G. Rakowsky, X.J. Wang, M. Woodle, V. Yakimenko, J. Jagger, V. Sajaev, I. Vasserman, Characterization of a high-gain harmonic-generation free-electron laser at saturation. Phys. Rev. Lett. 86, 5902 (2001)CrossRefGoogle Scholar
  4. 4.
    E. Allaria et al., Highly coherent and stable pulses from the FERMI seeded free-electron laser in the extreme ultraviolet. Nat. Photonics 6, 699 (2012)CrossRefGoogle Scholar
  5. 5.
    E. Allaria et al., Two-stage seeded soft x-ray free-electron laser. Nat. Photonics 7, 913 (2013)CrossRefGoogle Scholar
  6. 6.
    D. Gauthier et al., Spectro Temporal shaping of seed free-electron laser pulses. Phys. Rev. Lett. 115, 114801 (2015)CrossRefGoogle Scholar
  7. 7.
    E. Roussel et al., Multicolor high-gain free-electron laser driven by seeded microbunching instability. Phys. Rev. Lett. 115, 214801 (2015)CrossRefGoogle Scholar
  8. 8.
    H.P. Freund, Comparison of free-electron laser amplifiers based on a step-tapered optical klystron and a conventional tapered wiggler. Phys. Rev. ST-AB 16, 060701 (2013)Google Scholar
  9. 9.
    V.N. Litvinenko, High gain distributed optical klystron. Nucl. Instrum. Meth A304, 463–464 (1991)CrossRefGoogle Scholar
  10. 10.
    V.A. Bazylev, M.M. Pitatelev, Multisectional FELs with dispersion and undulator sections. Nucl. Instrum. Meth. A358, 64 (1995)CrossRefGoogle Scholar
  11. 11.
    N.A. Vinokurov, Multisegment wigglers for short wavelength FEL. Nucl. Instrum. Meth. A375, 264 (1996)CrossRefGoogle Scholar
  12. 12.
    H.P. Freund, G.R. Neil, Nonlinear harmonic generation in distributed optical klystrons. Nucl. Instrum. Meth. A475, 373 (2001)CrossRefGoogle Scholar
  13. 13.
    G.R. Neil, H.P. Freund, Dispersively enhanced bunching in high-gain free-electron lasers. Nucl. Instrum. Meth. A475, 381 (2001)CrossRefGoogle Scholar
  14. 14.
    Technical Design Report, The BESSY soft x-ray free electron laser.

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • H. P. Freund
    • 1
  • T. M. AntonsenJr.
    • 2
  1. 1.University of Maryland, University of New MexicoViennaUSA
  2. 2.University of MarylandPotomacUSA

Personalised recommendations