Figure 1: Generation of the terahertz FCS.
From: Phase-locking to a free-space terahertz comb for metrological-grade terahertz lasers
(a) Generation scheme of the terahertz pulses based on Cherenkov emission in a lithium niobate waveguide. (b) Terahertz comb spectral extension and single pulse temporal profile (inset) as measured with time-domain spectroscopy technique, using a photoconductive antenna as detector. The fast generation process, taking place in the LiNbO3 crystal, enables extension of the frequency range up to 6 THz. The 'comb-like' feature arises from the repetition of identical pulses equally spaced in time.
