Dual-comb interferometry using frequency shifting loops

Overview & Synopsis

Dual-comb systems have demonstrated their potential for metrology, e.g. spectroscopy vibrometry or ranging [1], However, the implementation of dual-combs is often complex and generally requires substantial optical optoelectronic hardware Here, we propose a simple compact architecture based on bidirectional frequency shifting loop, that provides more than I 00 mutually coherent comb lines The system makes use ofa CW laser slow electronic detection chain (10 MSa/s) We implemented two configurations enabling dynamic multi-heterodyne interferometry at 20kHz: first one acousto-optic shifters, allows highly sensitive distributed acoustic sensing along fiber, second involves electro-optic enables with sub-mm resolution.