Gas-plasma-based generation of broadband terahertz radiation with 640 mW average power

We present a high-power source of broadband terahertz (THz) radiation covering the whole THz spectral region (0.1-30 THz). The two-color gas plasma generation process is driven by a state-of-the-art ytterbium fiber chirped pulse amplification system based on coherent combination of 16 rod-type amplifiers. Prior to the THz generation, the pulses are spectrally broadened in a multipass cell and compressed to 37 fs with a pulse energy of 1.3 mJ at a repetition rate of 500 kHz. A gas-jet scheme has been employed for the THz generation, increasing the efficiency of the process to 0.1%. The air-biased coherent detection scheme is implemented to characterize the full bandwidth of the generated radiation. A THz average power of 640 mW is generated, which is the highest THz average power achieved to date. This makes this source suitable for a variety of applications, e.g., spectroscopy of strongly absorbing samples or driving nonlinear effects for the studies of material properties. (C) 2021 Optical Society of America

Automated summary

A high-power source of broadband terahertz radiation has been proposed, utilizing a gas plasma generation process. Leveraging an advanced ytterbium fiber chirped pulse amplification system, spectral broadening, pulse compression, and the highest average THz power to date have been achieved. This source is suitable for various applications including spectroscopy and material property studies.