We demonstrate high-speed distributed sensing based on slope-assisted (SA-) Brillouin optical correlation-domain reflectometry (BOCDR) using high-loss plastic optical fibers (POFs). Unlike the case of silica fibers, due to the gradual reduction in the transmitted power along the POF, the strain and temperature sensitivities are found to depend on sensing position. This unique effect is investigated both theoretically and experimentally, and then a correct POF-based distributed measurement is shown to be feasible by compensating this effect.
Power-based refractive index (RI) sensing is demonstrated by exploiting an ultrasonically pressed plastic optical fiber (POF). We can be easily and cost-efficiently fabricate this structure, within a short while ( ~1 s), without using external heat sources or chemical materials. We have only to simply press the horn connected to an ultrasonic transducer against part of the POF. The RI dependence of the transmitted power exhibits linear trends in the RI ranges from ~1.32 to ~1.36 (coefficient: −62 dB/RIU (RI unit)) and ~1.40 to ~1.44 (coefficient: −257 dB/RIU)). We also study the temperature dependence of the transmitted power.
We review the unique properties of a so-called optical fiber fuse phenomenon in plastic optical fibers (POFs), including its slow propagation velocity (1–2 orders of magnitude slower than that in silica fibers) and threshold power density (1/180 of the value for silica fibers). We also show that an oscillatory continuous curve instead of periodic voids is formed after the passage of the fuse, and that the bright spot is not a plasma but an optical discharge, the temperature of which is ~3600 K. We then discuss its impact on distributed Brillouin sensing based on POFs.