Speaker
Description
A high-power, tunable terahertz (THz) source based on an accelerator is currently under development at the Photo Injector Test facility at DESY in Zeuthen (PITZ) to support pump-probe experiments at the European XFEL Recent progress includes the successful demonstration of a single-pass THz free-electron laser (THz FEL), generating pulse energies exceeding 100 μJ at a central frequency of 3 THz. To fully characterize the THz output, precise measurement of both the temporal profile and electric field strength is essential. Electro-optic sampling (EOS) offers sub-picosecond resolution for time-domain measurements of the longitudinal electric field of THz pulses. This study presents the design and optimization of an EOS system tailored for the THz FEL at PITZ. Key design parameters—including the probe laser characteristics, optical configuration, and properties of the electro-optic crystal—are systematically refined to enable accurate temporal characterization of THz pulses centered between 1 THz and 5 THz. The design combines detailed modeling of THz wave propagation with numerical simulations of the EOS process to evaluate system performance under varying conditions. The optimized setup is expected to resolve THz pulse durations on the order of ~10 ps, enabling precise time domain characterization of the FEL output. These results will demonstrate the feasibility of EOS as a diagnostic tool for THz FEL experiments at PITZ.
