High Sensitivity of Temperature Sensor Based on Ultracompact Photonics Crystal Fibers

A temperature sensor with high sensitivity based on ultracompact photonics crystal fibers is proposed and analyzed by the finite-element method. The temperature-sensitive materials are injected into one cladding air hole, which shows high confinement loss and works as a defect core. As the phase-matched condition is satisfied, the power in the transferring core couples to the defect core. The temperature sensitivity and figure of merit reach to 2.82 nm/°C, 0.105/°C and 1.99 nm/°C, 0.048/°C, for the y-polarized and x-polarized directions, respectively, which are one to two orders of magnitude better than other reported sensors. The performance characteristics can be further improved by optimizing the structure parameters and infilling materials.