Fig. 1. Principle of sampling for terahertz dual-comb spectroscopy

Fig. 2. Schematic and experimental diagram of the optical path of the terahertz dual-comb spectroscopy system

Fig. 3. Measured terahertz spectrum signal with different repetition frequency difference

Fig. 4. The zoomed of the position of the water absorption peak

Fig. 5. The zoomed of the combs of the terahertz spectrum signal around 0.4894 THz