Specifications

14.07.2026, Website under construction, more details will follow.

THz source parameters

Superradiant undulator source

This is the default multicycle THz pump source offering intense frequency tunable THz pulses at flexible repetition rates. Please contact us to discuss your exact requirements. 

• THz frequencies and bandwidth: 0.1 THz to 2.5 THz, 20% (FWHM) frequency bandwidth. Best performance between 0.3 THz and 1.5 THz. The undulator generates (sub-)harmonics to a varying degree which can be filtered out using the available bandpass filters if a clean spectrum is required. 
• Repetition rate: Default is 50 kHz. This is the sweet spot between good statistics and high field strength. FPGA-based pulse-resolved detection for highest timing accuracy is currently only available up to 50 kHz. Lock-in based detection is always available. The latter comes with a timing jitter of approximately 100 fs (RMS), so that signals at frequencies > 1.5 THz can become smeared out. 
• Pulse energies and field strength: Pulse energies without filtering (i.e. with contributions from harmonics) are on the order of 1-10 µJ, maximum is reached between 0.5 THz and 1.2 THz (see figure below). Typical field strengths range from 100 kV/cm to 300 kV/cm, with the maximum around 1.0 THz. The field strength strongly depends on spot size. At the sample position the THz spot size is on the order of 1.5 mm (FWHM) for 0.3 THz and 0.8 mm for frequencies above 1.0 THz. However, this value depends strongly on sample environment and exact focusing geometry. Pulse energies are freely dimmable using a pair of motorized wiregrid polarizers.
• Polarization: Freely rotatable using available quartz quarter- and half-wave plates as well as a pair of wiregrid polarizers.