High-dynamic-range broadband terahertz time-domain spectrometer based on organic crystal MNA

We present a high-power and broadband terahertz (THz) time-domain spectroscopy setup utilizing the nonlinear organic crystal MNA both as an emitter and a detector. The THz source is based on optical rectification of near-infrared laser pulses at a central wavelength of 1036 nm from a commercial, high-power Yb-based laser system and reaches a high THz average power of 11 mW at a repetition rate of 100 kHz and a broad bandwidth of more than 9 THz without a significant power fall-off in the higher THz frequency components. The conversion efficiency is high (0.13%) in spite of the high excitation average power of 8 W. We validate the high dynamic range and reliability of the source for applications in linear spectroscopy by measuring the broadband THz properties of χ (2) nonlinear crystals up to 8 THz. This new high-repetition-rate source is very promising for ultra-broadband THz spectroscopy at high dynamic range and/or reduced measurement time.