Ultra-Sensitive Strain and Temperature Sensing Based on Modal Interference in Perfluorinated Polymer Optical Fibers

We implement the strain and temperature sensors based on multimode interference in perfluorinated (PF) graded-index (GI) plastic optical fibers, and investigate their sensing performance at 1300 nm. We obtain strain and temperature sensitivities of -112 pm/με/m and +49.8 nm/°C/m, the absolute value of which are 12.9 and over 1800 times as large as those in silica GI multimode fibers, respectively. These ultra-high strain and temperature sensitivities probably originate from the unique core material, i.e., PF polymer.