Self-referenced carrier frequency offset interferogram correction for dual-comb systems

Dual optical frequency comb (DOFC) has been unveiled as a prevailing tool for an increasing range of applications, such as molecular spectroscopy, ranging, imaging, and distributed sensing. Maintaining a high degree of temporal stability between the two mutually coherent interfering combs composing the DOFC is essential in emerging applications such as ranging and distributed sensing, where the amplitude and/or the phase profiles of subsequent interferograms are compared to extract time-varying information. In this work, we present a simple and efficient self-referencing correcting technique aimed at estimating and compensating for carrier frequency offset of time-domain interferograms. We validate our algorithm through a proof-of-concept spectroscopy experiment based on DOFC generated using optically injected gain-switched semiconductor lasers. Our experiments validate proper interferogram alignment with an SNR improvement of 38 dB along an interrogation time of nearly 0.2 s.