Broadband dual-comb spectroscopy with cascaded-electro-optic-modulator-based frequency combs

Dual-comb spectroscopy without mode-locked lasers is demonstrated in the telecommunication region. As a proof-of-principle, we measure Doppler-limited rovibrational spectra of the 2ν
₃
band of H
¹³
C
¹⁴
N spanning more than 4 THz with resolved comb lines.