Challenges and opportunities in distributed anti-Stokes Raman thermometry

Distributed sensing is a key requirement for the health and condition monitoring of several capital-intensive structures such as aerospace vehicles, bridges, dams, tunnels, oil/gas pipelines, and electric power distribution networks. Specifically, distributed temperature sensing is quite useful in several of the above applications, for which Raman scattering-based fiber sensors is a well-known solution. Distributed temperature sensing can be carried out by combining the Raman scattering phenomenon in optical fibers with optical time domain reflectometry (OTDR) to realize a Raman OTDR, and the overall method is referred to as distributed anti-Stokes Raman thermometry (DART). In this work, we have reviewed the current status, challenges and opportunities of DART system along with their potential applications.