Distributed sensing using frequency-selective fading

The fading phenomenon in optical time-domain reflectometry is regarded as a detrimental process that degrades measurement performance. In this study, we investigate the fading behavior of coherent Rayleigh backscattering. Using this characterization, we propose and demonstrate that fading can be utilized for distributed sensing. Using the frequency-selective response of fading and dual-pulse phase optical time-domain reflectometry, we demonstrate trace-to-trace strain measurements in a single mode fiber with a resolution below 3.3 n<i>ϵ</i>.