Recent advances in time-expansion distributed sensing technology

Time-expansion technology has emerged as a promising approach to enhance the spatial resolution of time-resolved distributed fiber sensing systems. By leveraging dual-frequency comb concepts, this technique enables a customized temporal expansion of retrieved traces, reducing detection requirements and improving efficiency. This method overcomes the conventional high-bandwidth detection limitations of centimeter-scale resolution systems while maximizing optical SNR and simplifying post-processing. In this contribution, we review the latest advancements in time-expansion technology, including SNR optimization and improvements in QIR configurations, and expose interesting applications of the technology, such as distributed and dynamic shape sensing.