Research On Fiber Bragg Gratings Based On Double-exposure Apodization

The principle and key technologies as well as the characteristics of the double-exposure apodization based FBGs had been studied. The research focuses primarily on the side-lobe suppression performance and the dispersion power. Furthermore, the simulated sensing network had been put up by adopting double-exposure apodizing FBG array. The main tasks were able to be concluded in three points below:1. The performance of side-lobe suppression in double-exposure FBGs which applied diverse apodizing function beams had been analyzed, according to the effect on the refractive index direct current component caused by corresponding function beams. Also, the reflection spectra of the FBG had been simulated and compared by means of Matlab and transmission matrix method. After inducing the best apodization function, the parameters of the best function had been analyzed in order to receive the optimizing conclusion.2. The latency curve of the double-exposure apodizing FBG had been portrayed by Matlab based on the latency and dispersion expression which was acquired by couple mode function and transmission matrix. Then dispersion compensation theory of double-exposure apodizing FBG had been introduced. Moreover, by means of theoretical calculation, the whole dispersion compensation condition had been deduced as well as the numerical analysis. Ultimately, double-exposure apodizing FBG, which had been provided the worked example, could be promoted in the domain of dispersion compensation.3. The simulated sensing network based on array that consisted of double-exposure apodizing FBGs had been established. With the data collected and processed by Virtue Instrument technology, the design of temperature sensing system was realized, which could operate 16 channels real time measurement and even extent to more than 70 channels for fulfilling the higher demand. Hereby, the application forecasting had been preliminarily predicted by provided the example.