The Novel Temperature Sensor By Using Mach-Zehnder Fiber Filter

This dissertation describes the development of optical fiber sensor system for application temperature sensor by using Mach-Zehnder interferometer. The Mach-Zehnder interferometer acquires fundamental importance because it can be used as a building block of more complex optical devices and functionalities such as optical filters, wavelength demultiplexers, intensity modulators, switches and optical gates.Mach-Zehnder interferometers (MZIs) are optical devices that make use of the interference between two optical signals from a same origin traveling through different effective path lengths.In this work, the performance of a Mach-Zehnder interferometer consisting of two coupled-cavity waveguides with different lengths created.In present work we first make two couplers and then a M-Z fiber filter is made by using these couplers with fusion splicer machine. We applied the M-Z fiber filter in two stages a) used M-Z fiber filter without metal sheet, b) used the M-Z fiber filter with attached metal sheets. Results for this experience showed that after using the metal sheets, the variations of frequency separation (f_s) can be increased. In stage without metal sheet for temperature from 30℃to 70℃the f_s only from 0.159 THz to 0.158 THz were changed whereas for attached 20 cm Al, the f_s were changed from 1.45 THz to 0.82 THz and for attached 20 cm Pb the f_s were changed from 0.62 THz to 1.49 THzrespectively.The present work is easily implemented in any environmental where the high sensitivity of temperature is necessary.