Fiber Bragg Grating Sensing Research

The fiber grating (FBG), as a new photo electronic device, enters the commercialization and integration along with the ripening technology for fabricating fiber gratings. The principle of FBG sensors is further discussed and the sensitivity of Bragg FBG stress /temperature sensor is measured in the original, which is usually used to form distributed sensors. Moreover, the mechanism and solutions of cross-sensitivity of FBG sensors will be mentioned.Chapter 1: Generality introducing the mechanism of optical fiber grating sensors, the fabricating technologies and categories of FBG. FBG written by UV which are high accuracy and favorable for people gradually, are extensively involved every part of fiber communication and used for sensors because of their unique characters.Chapter 2: Introducing the fundamental parameters of FBG and deriving the mechanism of FBG sensors in details. λB, which is the Bragg center reflection wavelength and the most significant parameter of FBG, is used to code being not affected by the fluctuation of source, the bending loss, the connection loss and the aging loss of detector etc. Cantilever is designed to tune FBG stress sensor and fiber Fabry-Perot tunable filter to survey it.Chapter3: Introducing the technology of wavelength division multiplex and demultiplex. Distributed sensors are the fundamental formation of FBG wavelength division multiplex, which key technology is demultiplex.Chapter 4: Measuring the sensitivity coefficient of FBG stress/ temperature sensor. The results tally with theories and the error is very little, which can be used to in the sensing system of FBG wavelength division multiplex system.Chapter 5: Introducing the mechanism and solutions of the cross- sensitivity of FBG sensors and the methods of enhancing sensitivity. The high sensitivity and the elimination of cross- sensitivity not only are easy to measure stress/temperature in the same time but protect FBG to adopt to work in the odious environment.