DAS Over 1,007-km Hybrid Link With 10-Tb/s DP-16QAM Co-Propagation Using Frequency-Diverse Chirped Pulses

We report the first distributed acoustic sensing (DAS) experiment with over >1,000 km reach on a hybrid link comprising of a mixture of field and lab fibers with bi-directional inline Raman amplification after each span. We used 20x frequency-diversity chirped-pulses for the probe signal, and recovered the Rayleigh backscatter using a coherent receiver with correlation detection and diversity combining. A measurand resolution of similar to 100 p epsilon/root Hz at a gauge length of 20 meters achieved in the offline experiment. We also demonstrate the first real-time FPGA implementation of chirped-pulse DAS without frequency diversity over a range of 210 km.

Automated summary

This study reports the first distributed acoustic sensing (DAS) experiment with a transmission distance of over 1,000 km. The experiment used a hybrid link consisting of field and lab fibers with bi-directional inline Raman amplification. A frequency-diversity chirped-pulse system was employed for the probe signal, and the Rayleigh backscatter was recovered using a coherent receiver with correlation detection and diversity combining. The experiment achieved a measurand resolution of approximately 100 p epsilon/root Hz at a gauge length of 20 meters in offline testing. In addition, the study demonstrated the first real-time FPGA implementation of chirped-pulse DAS without frequency diversity, covering a range of 210 km.