| As a new-type sensing element,fiber grating has gained abroad attention from it's appearance and achieved high-speed development in the last 20 years. With the development of fiber grating technology, study on the application of FBG sensor has got more recognition.As a new component of sensor , fiber grating have many instinctive advantages, such as light in weight, anti-cauterization, anti-interference in electromagnetism, high-sensitivity and compaction in construction. It is very easy to be coupled with fibers and the coupling-loss is slight. Using fiber grating's character of sensitivity for stress; people have done some envelope experiments on structural systems (such as storied buildings, bridge, railway and dam). Real-time detection and monitoring to stress (or strain) of structural systems have been put into effect. Martial researches in fiber grating hydrophone have also been developed.With the subjects supported by National Nature Science Fund Committee, Tianjin Science Committee, the main contents of this paper are as following:1 Depict generally on the sensor technique, and put emphases on the present situation and development of fiber and fiber Bragg grating sensor technique. Introduced briefly the developments, classification and the recent fabrication technology of fiber gratings. The application of fiber gratings in the fields of optical communication and the sensing are presented simply in this dissertation.2 Several theory analysis methods for properties of fiber gratings are presented including the coupled-mode theory, transfer matrix approach, multi-film method and Fourier transfer method. These methods have their own characteristics and scope of application. The methods of demodulation and multiplex technique used in fiber grating sensor are introduced in this dissertation.3 Using the FBG as the basic sensor unit, designed and fabricated fiber grating temperature and strain sensors which can be used for engineering application. |
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