Performance simulation and design comparison of optical heterodyne temperature sensor based on Fiber Bragg Grating

Abstract

In this work, an optical heterodyne temperature sensor system had been designed using Fiber Bragg Grating (FBG). Two techniques implemented. The first standard design uses dual laser diodes LDs as a laser sources that satisfy the condition of beat frequency range. The second new heterodyne optical system designed to get tunable source from single laser source using FBG, which is used as tunable element. By controlling the ambient temperature of the FBG, the wavelengths and their ranges can be controlled in way that satisfies the condition of beat frequency range. Mach-Zehnder interferometer (MZI) sensing technique had used with FBG element in both reference arm and sensing arm. Then the new modified heterodyne optical system had done by utilizing FBG in both reference arm and sensing arm with single source. A comparison study of results by using Optisystem software shows that, the modification of the second design provides better performance by increasing the wavelength shift and the sensitivity of the modified heterodyne temperature sensor.