Rapid THz-TDS enabled by single-cavity solid-state GHz dual-comb oscillator

We present THz-TDS with a low-noise single-cavity dual-comb GHz oscillator. This solid-state laser delivers two mutually coherent combs with 70-fs pulses, 1055-nm center wavelength, 110 mW per comb, and a repetition rate difference up to 100 kHz. In a proof of principle THz experiment, we direct the two combs onto two photoconductive antennae to efficiently generate and electrooptically sample the THz waveform. At a repetition rate difference of 37 kHz we achieve 40-dB dynamic range in a 2-s integration time for a spectral resolution of 2 GHz allowing to resolve absorption features up to 3 THz.