Average-power scalability of multi-cycle terahertz sources based on periodically poled lithium niobate stacks
Patrick J. Dalton, Robin Löscher, Tim Vogel, Robert B. Appleby, Graeme Burt, Steven P. Jamison, Morgan T. Hibberd, Darren M. Graham, Clara J. Saraceno
Published: 2025/9/16
Abstract
We demonstrate that narrowband multi-cycle terahertz (MC-THz) sources based on periodically-poled lithium niobate (PPLN) wafer stacks can be driven by high repetition-rate, high energy femtosecond ytterbium-doped lasers. Operating at 10-kHz repetition rate with up to 104 W of pump power on a 10-wafer stack, we measure 26.4 mW of THz average power for a narrowband multi-cycle source. We identify and quantify strong lensing effects causing dramatic beam focusing in 47 wafer stacks which act as a primary limitation in the current configuration, and present mitigation strategies for future scaling. This first study of high average power narrowband multi-cycle THz sources offers a path forward to Watt-level high repetition rate sources using thin lithium niobate plates.