A Survey on Simulation Method for Wave Propagation in Fiber Brag Greeting

In recent years, many research and development projects have focused on the study of fiber Bragg gratings. Fiber Bragg gratings have been used in the field of sensors, lasers and communications systems. Commercial products that use fiber Bragg gratings are available. On the other hand, in the field of software development, object-oriented programming techniques are also becoming very popular and powerful. For fiber Bragg grating problems, widely used theories and numerical methods such as the coupled-mode theory and the transfer matrix method will be applied in the analysis, modeling and simulation. The coupled-mode theory is a suitable tool for analysis and for obtaining quantitative information about the spectrum of a fiber Bragg grating. The transfer matrix can be used to solve non-uniform fiber Bragg gratings. Two coupled-famode equations can be obtained and simplified by using the weak waveguide approximation. The spectrum characteristics can be obtained by solving these coupled-mode equations. Uniform, chirped, apodized, discrete phase shifted and sampled Bragg gratings have already been simulated by using the direct numerical integration method and the transfer matrix method. The reflected and transmitted spectra, time delay and dispersion of fiber Bragg gratings can be obtained by using this simulation program. At the same time, the maximum reflectivity, 3dB-bandwidth and centre wavelength can also be obtained.