Novel OFDR enhanced by dual microcombs

Optical frequency combs offer groundbreaking tools for advanced metrology and sensing. The invention of microcombs promotes the practicality of optical frequency combs greatly. In this work, we propose and demonstrate a novel optical frequency domain reflectometer (OFDR) concept based on dual-microcombs. By combining dual-microcombs and tunable laser source, this novel OFDR can significantly enhance the strain sensitivity (up to 177.8 pε/√Hz) by a √N-fold (here N is the number of the microcomb lines used) via superposition of multi-frequency signals, while maintaining superior spatial resolution (under 0.82 mm) for precise localization and large response bandwidth (achieved 1 kHz). This work may lead to the realization of new OFDR that can achieve distributed dynamic sensing with high sensitivity, high spatial resolution and large bandwidth simultaneously.