Broadband, High-Power and High Repetition Rate Terahertz Time-Domain Spectrometer Based on Organic Crystal MNA

Laser-driven pulsed terahertz (THz) sources have gained popularity in various scientific and technological fields due to their ultra-broad bandwidths and high sensitivity when detected using coherent THz time-domain spectroscopy (THz- TDS). The dynamic range (DR) is a crucial metric for optimizing THz- TDS performance, which can be enhanced by increasing the single THz pulse strength and/or averaging multiple pulses. Novel THz-TDS with higher pump pulse strength and high repetition rates offer broader bandwidths and higher DR, essential for wide verity of applications such as linear spectroscopy in much faster measurement time. Optical rectification (OR) and electro-optic sampling (EOS) in organic crystals, present a promising solution for scaling THz average power and bandwidth at a high repetition rate due to high nonlinear coefficient. Although state-of-the-art organic crystal-based sources have shown impressive results in terms of bandwidth and electric field, they often lack the THz average power needed to achieve DR and high bandwidth results in a short amount of measurement time [1]. In this context, MNA (2-Amino-5- Nitrotoluene) is a good candidate as it offers good surface quality, and good phase-matching condition at pump wavelength of 1030 nm where Ytterbium (Yb)-based lasers operate [2] and has so far not been explored at this driving wavelength.