Fiber-Optic Temperature Sensor Design Adapted for Libyan Environment

Abstract

In this work, the design of the Fiber optic Temperature Sensor has been performed using two different techniques aimed at determining the optimum design parameters of the fiber optic sensor that should work properly in the Libyan environment (temperature: -13 to 57.8 degrees Celsius). The first technique is based on Fabry-Perot Interferometer that tracks the phase change of the received light by the interferometer due to the sensitivity of the Fabry-Perot’s cavity to the surrounding temperature changes. Three different substances (GaAs, Ge and Si) were used in determining the optimum design parameters of the fiber optic sensor. The optical wavelength used is 1550nm with line width of 40nm. The material selected is Si where the optimum Fabry-Perot length was found to be 20.7µm. The second technique studied is based on Fiber Coupling Actuated by a Bimetal Strip to read the change in temperature with respect to coupling power loss. Three different standard Bimetal types were used for the design of the strip, (KANTAL 200 TB20110 Ni/MnNiCu), (KANTAL 135 Ni/NiMn-steel) and (KANTAL100 TB0965 Ni/NiMn-steel). The (KANTAL 200 TB20110 Ni/MnNiCu) Bimetal material was selected for the optimal sensor design. The optimum design length, delta deflection and thickness for the strip were found to be 5.6µm, 35µm and 1.3µm respectively.