Microstructured fibre humidity sensor and application for human breathing sensing

摘要

The advent of new optical fibre technologies in recent years have revolutionized the telecommunications and sensing field. In particular the rapid development of microstructured fiber, also known as photonic crystal fiber (PCF), brings about remarkable features such as air guided mechanism, unique geometric structure and single material fibre structure that could overcome many limitations intrinsic to conventional standard optical fibers.This thesis reports my research and original results from the development and application of microstuctured fibre as fiber humidity sensors. My work covers the design and fabrication of the PCF-based sensors, development of experimental systems with related data generation and acquisition capabilities, novel sensing schemes and techniques as well as proof of concept experiments. I proposed and experimentally demonstrated several novel fibre humidity sensor schemes which do not require coating of any hygroscopic or sensitive film while most of previous reported fiber humidity sensors need the hygroscopic films to sense humidity. I also proposed and demonstrated a microstructured optical fibre based humidity sensor for respiration monitoring for possible application of PCF-based fiber sensors in the bio-medical engineering field.