Broadband THz Emission from LT-GaAs Photoconductive Antenna Driven by Yb-Doped Fiber Amplifier at 200 kHz Repetition Rate

Terahertz (THz) pulses associated with strong electric fields (> few tens of kV/cm) allow the investigation of nonlinear light-matter interactions [1], THz-induced phase transitions [2], and collective excitations of ordered phases [3]. While current sources of intense THz pulses are mostly driven by femtosecond infrared pulses from low repetition rate laser amplifiers (∼ 1 kHz), many THz-based spectroscopic techniques also require a high signal-to-noise ratio. In this context, high-power femtosecond fiber lasers with energies of a few hundreds of $\mu\mathrm{J}$ operating at repetition rates higher than 100 kHz have started to occupy a predominant place in the THz domain. For instance, mW-level and high-field THz generation driven from optical rectification in nonlinear crystals at high repetition rates have been demonstrated recently [4].