A new type of fiber sensor has been developed for structural damage monitoring through fiber networks. The sensor utilizes a short-length, different core-size fiber insertion in a single-mode-fiber network line.
Kaori Tajima, Kaori Tajima,
"Development of a hetero-core fiber sensor", Proc. SPIE 3746, 13th International Conference on Optical Fiber Sensors, 374627 (1 September 1999); doi: 10.1117/12.2302069; https://doi.org/10.1117/12.2302069