Design and development of cost-effective fiber Bragg grating temperature sensor package

Abstract

A cost-effective fiber Bragg grating (FBG) temperature sensor package was designed and developed with two distinct sensing probes and demodulation schemes. U-shaped and capillary shape probes were designed and tested using an optical spectrum analyzer and two different indiginously developed intensity demodulation schemes. The temperature sensitivities were measured as 12.94 ± 0.15 pm °C−1, 11.57 ± 0.12 pm °C−1, and 12.03 ± 0.14 pm °C−1 for a bare FBG and for FBGs encapsulated in the U-shaped and capillary probes, respectively, with negligible hysteresis and a repeatability of 1 °C–3 °C. The performance of the probes was demonstrated by twin-FBG intensity demodulation schemes, the range of which was increased up to 181.50 °C with a resolution of 0.120 °C by the development of a CFBG-FBG intensity demodulation scheme.