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

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 degrees C-1, 11.57 +/- 0.12 pm degrees C-1, and 12.03 +/- 0.14 pm degrees 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 degrees C-3 degrees C. The performance of the probes was demonstrated by twin-FBG intensity demodulation schemes, the range of which was increased up to 181.50 degrees C with a resolution of 0.120 degrees C by the development of a CFBG-FBG intensity demodulation scheme.