The FELBE FELs are the only FELs in Europe providing ultrashort pulses at a continuous high repetition rate (13 MHz). The two FELs of FELBE provide continuous tunability over a spectral range of 5 µm - 250 µm (U37 : 5 µm - 40 µm, U100 : 20 µm - 250 µm) with a bandwidth of ~0.4 - 3% and a maximum average power up to tens of Watts, corresponding to pulse energies of a few µJ.  The ultrashort pulsewidth scales with the wavelength, ranging from sub-ps to a few tens of ps, resulting in a maximum peak power within each pulse of ~ 1 MW and fields up to MV/cm. The high repetition rate (13 MHz) and high average power enable exceptional signal-to-noise and data statistics, but additional time structures such as a macropulse (burst) mode or lower repetition rates by pulse-picking are also available.

The FELBE FEL beam is directed into several user labs equiped with a wide range of instrumentation and synchronized tabletop sources for time-resolved and nanoscale measurements in specialized sample environments (e.g. pump-probe, s-SNOM, low-temperature, etc.). Measurements in high magnetic fields are also possible in both static fields up to 7 T or with the worlwide unique experimental capability of the FELBE FEL beamline extending to a pulsed magnetic field up to 70 T (in 100+ ms pulses) in the Dresden High Magnetic Field Laboratory (HLD).

Photon Source Parameters

FELBE Parameters

FEL mode
FEL oscillator
Photon energy range / wavelength range
5 - 250 [um]
Spectral Bandwidth FWHM / %
0.4 - 3.4 [%]
Beam shape
Pulse duration FWHM
10 [ps]
Pulse Duration Min Max
0.7 - 25 [ps]
Linear Horizontal
Pulse repetition rate
13 * 106 [Hz]
Maximum pulse energy
5 * 10-6 [J]
Peak power
1.5 * 106 [W]
Special modes
FEL pulses are available in time structure modes of either continuous 13 MHz, macropulse (burst), or pulse-picking (1 kHz).
Several synchonized tabletop laser sources and laser driven THz sources are available for performing two-color pump-probe experiments with the FEL source. Some of the lasers can be combined with OPAs for broader tunability. Sample environments for low-temperature and high magnetic fields (up to 7 T DC or up to 65 T pulsed) are also available for users.
Michael Klopf
  • IR spectroscopy
  • Time-resolved studies
Emission or Reflection
  • Time-resolved studies
  • IR Microscopy
  • THz near-field microscopy
  • Biochemistry
Engineering & Technology
  • Detectors
Life Sciences & Biotech
  • Biophysics
Material Sciences
  • Other - Material Sciences
  • Dynamics
  • Hard condensed matter - electronic properties
  • Hard condensed matter - structures
  • High-field science, non-linear X-ray Optics
  • Nanophysics & physics of confined matter
  • Optics
  • Other - Physics
  • Quantum electronics & optics
  • Soft condensed matter physics
  • Surfaces, interfaces and thin films
control/Data analysis
Control Software Type
  • coming soon
Data Output Type
  • coming soon
Data Output Format
  • coming soon