The Novel Temperature Sensor by Using Mach-Zehnder Fiber Filter

论文摘要

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 （fs） can be increased. In stage without metal sheet for temperature from 30℃to 70℃the fs only from 0.159 THz to 0.158 THz were changed whereas for attached 20 cm Al, the fs were changed from 1.45 THz to 0.82 THz and for attached 20 cm Pb the fs 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.

论文目录

• Abstract
• Table of Contents
• List oa abbreviations and symbols
• CHAPTER 1 Introduction of Fiber Optic Sensor
• 1.1 Introduction
• 1.2 Fiber Optic Sensor
• 1.3 Classification of Fiber Optic Sensors
• 1.3.1 Extrinsic Sensors
• 1.3.2 Intrinsic Sensors
• 1.4 Advantages of Fiber optic Sensors （Benefits）
• CHAPTER 2 Structure of Fiber Optic Sensor
• 2.1 Electromagnetic spectrum
• 2.2 Windows
• 2.3 Types of Sensors
• 2.3.1 Intensity Modulated Sensors
• 2.3.2 Spectrally Modulated Sensors
• 2.3.3 Phase Modulated Sensors
• 2.4 Temperature sensors
• 2.5 Interferometer Sensors
• 2.5.1 Sagnac interferometer （Fiber Optic Gyroscope）
• 2.5.2 The Mach-Zehnder and Michelson interferometer
• 2.6 Mach-Zehnder structures
• CHAPTER 3 Introduction and fundamental of couplers
• 3.1 Couplers
• 3.2 Couplers sizes
• 3.3 Losses
• 3.3.1 Excess loss
• 3.3.2 Directionality loss or cosstalk or directivity
• 3.3.3 Insertion loss or port-to- port loss or throughput loss or tap loss
• 3.3.4 Coupling loss
• 3.4 Coupling tolerance
• 3.5 Coupler machine model GYCW-4
• 3.5.1 Requirement of environment
• 3.5.2 Facility requirements
• CHAPTER 4 Method of Fusion for Fiber Optic Splicing
• 4.1 Temperature- Controller unit device
• 4.2 Optical Spectrum Analyzer （Spectrometer）
• 4.3 Fusion
• 4.4 Fused couplers
• 4.5 Methods of fiber optic splicing
• 4.6 Mechanical and fusion splicing
• 4.6.1 Mechanical splicing
• 4.6.2 Fusion splicing
• 4.7 Fusion splicer instrument
• 4.8 Fusion splicing method
• 4.8.1 Fusion splice steps
• 4.9 Loss estimation
• 4.10 Mechanical splicing method
• 4.10.1 Mechanical splice steps
• 4.11 Tips for better splices
• 4.12 Main fuse
• CHAPTER 5 Temperature sensors by using Mach-Zehnder fiber filter
• 5.1 Mach-Zehnder fiber filter
• 5.2 Experiment principle
• 5.3 Experiment setup
• 5.3.1 System setup without use metal sheet
• 5.3.2 System setup with attached metal sheets
• 5.3.2.1 System setup for attached 20 and 30 cm aluminum sheets
• 5.3.2.2 System setup for attached 20 and 30 cm lead sheets
• 5.4 Conclusion
• Reference
• Acknowledgements