High sensitivity temperature sensor based on Fresnel reflection with thermosensitive polymer: control of morphology and coating thickness

Abstract

We propose and experimentally demonstrate a simple fabrication and high sensitivity FabryPerot interferometer polymer (FPIP)-coated temperature sensor based on Fresnel reflection. The single mode fiber end-face was coated with a polycarbonate (PC) or poly(methyl methacrylate) (PMMA) thermosensitive polymer. The experimental results indicate that the FPIP sensor coated with PMMA exhibits the average temperature sensitivities of 312.5 and 257.0 pm degrees C-1 for the thicknesses of 5.2 and 6.5 mu m, respectively, in the temperature range of 26 degrees C-80 degrees C. Meanwhile, the FPIP sensor coated with PC exhibits the average temperature sensitivities of 245.4 and 103.6 pm degrees C-1 for the thicknesses of 4.9 and 9.9 mu m, respectively, in the temperature range of 26 degrees C-140 degrees C. The FPIP sensor coated with PC indicates a relatively low sensitivity compared to PMMA coated sensor. However, the available operating temperature range for PC sensor is larger than PMMA. (C) 2020 The Japan Society of Applied Physics