Locally pressed plastic optical fibers for refractive index sensing

Abstract

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.