A Laser-Activated Plasma Switch for the Extraction of Single FELBE Radiation Pulses


A Laser-Activated Plasma Switch for the Extraction of Single FELBE Radiation Pulses

Seidel, W.; Winnerl, S.

In order to decrease the average radiation power of the Rossendorf free-electron laser FELBE, as required for certain experiments (high pulse energies but moderate or low average power), the FEL repetition rate can be reduced from 13 MHz to 1 kHz. To this end, plasma switching of FEL radiation pulses was demonstrated for cw operation. The plasma switch is based on the principle of photo-induced reflectivity by an optically excited electron-hole plasma. Germanium or silicon serves as semiconductor material for the switch. The semiconductor was illuminated by a Nd:YAG laser amplifier system (1 kHz, wavelength 1064 nm, pulse duration16 ps, 1Watt), generating an electron-hole plasma on the front surface of the semiconductor. To integrate this plasma-switch into the existing experimental set-up we build an additional by-pass to the Germanium or Silicon slab which is under Brewster’s angle. To get a high contrast in the switched beam we adjust the polarization plane of the incoming beam to the right direction by using an additional polarization rotator. We will report on first results at different wavelength. Submitted as a poster to the FEL 2010 conference.

Related publications

  • Poster
    Free Electron Laser Conference, 23.-27.08.2010, Malmö, Sweden
  • Contribution to proceedings
    Free Electron Laser Conference, 23.-27.08.2010, Malmö, Sweden
    Proceedings of the FEL 2010

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Publ.-Id: 14606