Study Of The Embedded Composite FBG Sensor

Fibers Bragg grating (FBG) sensors is an optical passive device and develops quickly in the last decades. As which having advantages such as immunity to Electromagnetic Interference (EMI), Radio Frequency Interference (RFI), and accuracy etc, FBG has bright prospects of application in fiber communication and sensing. But in fact, the FBG is fragile, tended to break and subjected to alkali, so these kinds of FBG sensors are far away out of the requirements of project monitoring in industry. As a result, it is necessary to look for effective packaging methods to protect the FBGIn order to resolve those disadvantages, one new kind of composite-matrix FBG sensor is researched in this paper. As the programmable of the packaged material, it can receive a good effect when match the FBG with fundus material. And it can also reduce error and improve the linearity. At the same time, the encapsulation technique and the influence of encapsulation methods to results are expatiated in the work.Main research work of this paper as follows:1. Analyze the strain characteristics and the influence of wavelength change on strain sensitivity of bare Bragg grating base on transmission theory of Bragg grating.2. Research one kind of sensor packaged with T300/648 composite and studies its characteristics with cantilever bending test. Investigation the influences of the encapsulation technique to the performances of FBG3. Research the interface transfer theory and the error revise and deduce their formulas of FBG sensor. And use these formulas to correct those results detect by composite-matrix FBF sensor.According to study and perform some theoretical analyses on the experimental results, we draw some conclusions as follow:1. The packaged FBG with composite matches well with fundus material and which can also improve the precision of the test.2. The packaged FBG has higher temperature sensitivity than that of bared FBG3. The waved-shape of packaged FBG is in good condition and doesn't bring chirp.4. The packaged FBG still has a good linearity between reflecting wavelength and strain or temperature.