Researches On Multiplexing And Demodulation Technique Of Fiber Grating Based On Particle Swarm Optimization-simulated Annealing Algorithm

With the development of optical fiber sensing technology, a variety of novel fiber sensor is developed. FBG has the advantage of low cost, light weight, immune to electromagnetic interference and ready for multiplexing, of which ready for multiplexing is its outstanding advantage. At present, the demodulation and recognition to multiplexed sensor network is a difficult. The peak detection which wavelength division multiplexing and time division multiplexing make use of limits the number of multiplexing gratings. When the spectra of FBGs within the network are partially or fully overlapped, the crosstalk between sensors and introduced errors would appear. In this paper, we use the particle swarm simulated annealing algorithm to identify the sensor network which is formed by the spectra shape multiplexing technology. In theory, the recognition of 2, 3and 4 grating multiplexing are discussed. At the same time, the overlapping spectra of FBG in the temperature and strain multiplexing sensor network are identified. The spectra research work is as follows:Firstly, the development history, the current situation of fiber grating and the application of fiber grating are introduced in this paper.Secondly, the sensing properties of FBG are studied, several common demodulation techniques and multiplexing methods are introduced, whose principle is analyzed in detail.Then, the principle and implementation process of particle swarm optimization and simulated annealing algorithm are studied in-depth. And the advantages and disadvantages of the 2 algorithm are analyzed in detail. Then the particle swarm simulated annealing algorithm is formed by combining the 2 algorithm. The recognition of spectral shape multiplexing network is achieved using the new algorithm.Finally, the identification of multiplexing network with different number of gratings is achieved using particle swarm simulated annealing algorithm in theory. The temperature and strain sensing multiplexed experiment are set up. And the two experiment systems are demodulated using the optimization algorithm.