Distributed optical fiber sensing: Review and perspective

TLDR

Optical fibers, originally deployed for high‑speed telecommunication, imaging, and lasers, have evolved into distributed sensors that provide spatially resolved measurements along a single fiber, becoming the leading technology in optical sensing. This review surveys Rayleigh, Brillouin, and Raman‑based distributed fiber sensors and their demodulation techniques, emphasizing recent advances in energy‑related monitoring and outlining challenges to extend their practical deployment. The authors analyze simultaneous multi‑parameter sensing schemes, comparing OTDR, OFDR, and related demodulation methods, and discuss the trade‑off among sensing range, spatial resolution, and sensing resolution.

Abstract

Over the past few decades, optical fibers have been widely deployed to implement various applications in high-speed long-distance telecommunication, optical imaging, ultrafast lasers, and optical sensors. Distributed optical fiber sensors characterized by spatially resolved measurements along a single continuous strand of optical fiber have undergone significant improvements in underlying technologies and application scenarios, representing the highest state of the art in optical sensing. This work is focused on a review of three types of distributed optical fiber sensors which are based on Rayleigh, Brillouin, and Raman scattering, and use various demodulation schemes, including optical time-domain reflectometry, optical frequency-domain reflectometry, and related schemes. Recent developments of various distributed optical fiber sensors to provide simultaneous measurements of multiple parameters are analyzed based on their sensing performance, revealing an inherent trade-off between performance parameters such as sensing range, spatial resolution, and sensing resolution. This review highlights the latest progress in distributed optical fiber sensors with an emphasis on energy applications such as energy infrastructure monitoring, power generation system monitoring, oil and gas pipeline monitoring, and geothermal process monitoring. This review aims to clarify challenges and limitations of distributed optical fiber sensors with the goal of providing a pathway to push the limits in distributed optical fiber sensing for practical applications.