Strain and temperature sensing based on multimode interference in partially chlorinated polymer optical fibers

We develop strain and temperature sensors based on multimode interference in a partially chlorinated graded-index polymer optical fiber (PCGI-POF) and experimentally investigate their sensing performance at room temperature using incident light of ∼1300 nm wavelength. The length of the PCGI-POF was 0.7m. The measured strain and temperature sensitivities were −4.47 pm/με and +9.66 nm/°C/m, respectively, the absolute values of which were 0.29 times and over 350 times the values in a silica GI-MMF. This result suggests that the modal interference in PCGI-POFs is potentially applicable to high-sensitivity temperature measurement with low strain sensitivity.