Dual-Comb Swept-Wavelength Interferometry: Theory and Experiment

Much efforts have been put to elaborate and im-prove different high precision measurement schemes for char-acterization of advanced photonic devices and optical fibers with increasing bandwidth requirements. In light of this, swept-wavelength interferometry and dual-comb spectroscopy have been extensively applied in characterization procedures. In this paper we present in detail an experimental scheme that combines these two techniques and overcomes their limitations by using a tunable laser source in order to sweep over the the frequency comb spacing and capture all intermediate frequencies. We demonstrate full-field broadband measurements over 1.25 THz comb bandwidth with increased frequency resolution which can be performed just in 5 ms sweep and show that nonlinearity of the laser sweep can be removed without an auxiliary interferometer in the setup.