Study On Fiber Bragg Grating Array And New Devices Using For Fiber Grating Sensing Network

The large-scale optical fiber sensing network was developed rapidly. Using traditional discrete fiber devices to construct such a network not only faces with technical obstacles, but also encounters more and more difficulties in manufacturing technology. The development of fiber grating technology, provides a new industrial production way for the construction of large-scale optical fiber sensing network. In these systems, fiber grating has been not just one wavelength device or single sensing unit, but rather as one functional device in large-scale optical fiber sensing system and manufacturing technology in industrial fields. With the development of fiber grating technology, different structures, different functions and multi-function optical fiber grating devices appear, which makes the construction of fiber grating sensing network which has more complex and more good performance is possible. These develop more applications for fiber Bragg gratings and the related system, meanwhile, put forward a series of new issues for the basic theory.Based on the background of large-scale fiber Bragg grating sensing array, the system theory, manufacturing technology and testing technology for multiple groups fiber Bragg grating on one single optical fiber were completely studied. Theoretical and experimental studies on fiber grating coupler, fiber polarizing grating and micro/nano fiber grating were carried on. The development of these new devices will provide new support for the development of large-scale fiber grating sensing network.The main results of the paper are as follows:1. The composite system which has multi-group fiber Bragg gratings on one single fiber was studied. Manufacturing technology and online real-time monitoring technology of multi-group low reflectivity FBGs independent performance on single fiber have been realized, which solved the key problem for manufacturing and application of fiber grating sensing network.2. The fused-tapered fiber grating coupler was successfully produced. This composite device has special wavelength selective and transmission characteristics, which can add or drop optical signal of single special wavelength in complex all-fiber network.3. We proposed an integrated miniaturized device--fiber Bragg polarizing grating. Through the three-dimensional composite waveguide model, the polarization properties were analyzed. The polarization maintaining fiber polarizing grating was produced using special technology. This device was used in fiber ring laser to instead of two devices, and the laser achieved the statement of single polarization single longitudinal mode. The application of fiber polarizing grating will make the complex fiber grating sensing network has the ability of polarization controlling.4. The micro/nano fiber Bragg grating was studies. The experiments on micro tension and chemical parameter sensing were carried out. The 40.001nm/N high sensitivity of micro tension measurement which was in 156 times higher than that of conventional fiber grating and 0.038% concentration changes of salt solution detection were realized. The use of micro/nano fiber grating will further promote the miniaturization and high sensitivity of fiber grating sensing network.