Author: Joly, N.Y.
Paper Title Page
MOPB16 New Tunable DUV Light Source for Seeding Free-electron Lasers 38
 
  • N.Y. Joly, W. Chang, P. Hölzer, J. Nold, P.St.J. Russell, J.C. Travers
    Max Planck Institute for the Science of Light, Erlangen, Germany
  • M.-E. Couprie, M. Labat
    SOLEIL, Gif-sur-Yvette, France
  
  Seed­ing of sin­gle-pass free-elec­tron lasers is a promis­ing ap­proach for im­prov­ing the tem­po­ral co­her­ence com­pared to self-am­pli­fied spon­ta­neous emis­sion [1], at the same time re­duc­ing the sat­u­ra­tion length and re­in­forc­ing the har­monic level. Con­ven­tion lasers or har­mon­ics gen­er­ated in gas are usu­ally used as co­her­ent seeds [1]. How­ever such sources re­quire com­pli­cated set-up and have lim­ited tune­abil­ity. Here, we sug­gest the use of a newly dis­cov­ered and ef­fi­cient source of UV light, con­tin­u­ously tun­able from 120 nm to 320 nm. The ex­tremely com­pact and sim­ple set-up con­sists of 20 cm of hol­low-core pho­tonic crys­tal fibre filled with a noble gas at vari­able pres­sure up to a few tens of bar and pumped by ~1 μJ 30 fs pulses at 800 nm [2]. The process re­lies on a favourable se­quence of lin­ear and non­lin­ear ef­fects: low pres­sure-tun­able dis­per­sion, pulse com­pres­sion due to a com­bi­na­tion of self-phase-mod­u­la­tion and anom­alous dis­per­sion, self-steep­en­ing and dis­per­sive wave gen­er­a­tion. Tun­able dif­frac­tion-lim­ited DUV pulses of ~50 nJ and fs du­ra­tion are gen­er­ated. Seed­ing of FEL is dis­cussed.
[1] G. Lambert et al., Nature Physics 4, 296-300 (2008)
[2] N. Joly et al., accepted in PRL