The Analysis and Simulation on the Mode coupling Characteristics of Long period Fiber Grating

This paper mainly presents the analysis and simulation on the mode coupling characteristic of long period fiber grating,focusing on the research of cladding mode field distribution and coupling coefficients.With the aid of simplified three layered model,we use Matlab to simulate the results,and get the cladding mode field and intensity distribution.The numerical results make it clear that the coupling between the core mode and the first rank odd order cladding modes is much stronger than the coupling between the core mode and the first rank even order cladding modes.We use the graphical method and the simplified calculation to get the result,which can be compared with oversea publications.