Info for Users
The TeraFERMI beamline is opening to external users. The beamline operates in parasitic mode along regular FERMI-FEL user shifts at 10 or 50 Hz repetition rate.
At time of writing the beamline routinely provides sub-ps THz pulses with energy ranging between 10 and 50x10-6 Joule per pulse at sample position in a spectrum extending between 0.2 and 6 THz. Sample size at focus is < 0.5 mm FWHM.
Various classes of experiments are available at TeraFERMI:
- In a typical fluence-dependent experiment it is possible to measure the optical properties of the materials under study as a function of the incoming energy, in order to address its non-linear properties. The fluence at sample can be varied by either scanning the sample along the beam direction (thus varying the spot size) or by employing crossed polarizers. The frequency-dependent spectrum can be recorded either with a step-scan Michelson interferometer or with optical filters.
- THz pump-THz probe experiments can be performed by splitting the beam from TeraFERMI in two different paths and varying the relative delay between the two in jitter-free experiments
- THz pump - IR (780/1560 nm) probe experiments are made possible by the presence of <100 fs pulses from an oscillator synchronized with FERMI
- Electro-optic sampling schemes are also available
The use of cryogenic, high-pressure, liquid environment set-ups can be implemented upon request.
We invite users and collaborators to discuss their proposals with the beamline local contacts well in advance of the submission deadline. This is crucial for a careful assessment of the experiment feasibility and may result in an improvement of the proposal.
