A compact terahertz source for time-resolved terahertz pump–EUV probe experiments at FERMI

Over the past decade, the widespread use of tabletop high-field terahertz (THz) sources has enabled the scientific community to investigate ultrafast dynamics within the "THz gap" (0.1 – 10 THz). In this context, we developed a compact, in-vacuum THz source to be integrated into the DiProI endstation of the FERMI free-electron laser, enabling THz pump–EUV probe experiments. Our source is based on optical rectification in a BNA organic crystal, generating quasi-single-cycle THz pulses with a peak amplitude of approximately 300 kV/cm and a spectrum centered at 1.2 THz. This talk will present a detailed characterization of the THz source, along with examples of its potential applications.