Optical Waveguide Finite Element Beam Propagation Method Analysis in Time Domain
|Keywords||Finite Element Method Time-domain beam propagation method Meshing Planar waveguide Photonic crystal fiber|
With the development of optical communication network technology, various kinds of optical waveguide devices get in-depth study of its the increasingly novel structure, increasing performance. Analysis of optical waveguide the lightwave transmission characteristics and looking optimization method for the design of new devices, has become the focus of all kinds of practical photonic devices ring. The emergence of photonic crystal waveguides and photonic crystal fiber, leading to changes in traditional optical waveguide light guide mechanism and analysis methods. Conventional optical waveguide numerical analysis method is difficult to meet the demand for complex optical waveguide and the periodic structure analysis, must be efficient and accurate numerical analysis method. As an important method of numerical analysis, finite element method with the characteristics of the adaptability of the optical waveguide any shape, high calculation accuracy, the optical waveguide analysis play an increasingly important role. Therefore, to explore optical waveguide finite element analysis method to establish a corresponding mathematical model, developed a practical design software, has an extremely important significance of the results obtained in the analysis and research of optical waveguide devices will play a guiding role. Firstly, starting from the Maxwell equations, derived optical waveguides in optical electromagnetic transmission Euler equation characterization of two-dimensional plane, be divided finite element discrete model. Triangular element nodes Automeshening algorithm using linear interpolation, numerical simulation of the ridge waveguide the main waveguide mode and the mode field distribution. The results are consistent with the recently published results of the international core journals. While using ANSYS simulation, and on the same ridge waveguide and before the results of comparison analysis demonstrated the correctness and validity of the finite element model established in this paper. Followed by, respectively, the establishment of a three-dimensional optical waveguide scalar, vector finite element analysis model to discuss the boundary conditions to determine the principles of pseudo solutions reasons and to avoid its method, finite element analysis were rectangular and cylindrical waveguide. Discussed in detail in Chapter 4 of the finite element analysis meshing, give examples and analysis of two-dimensional / three-dimensional triangular and quadrilateral meshing computational approaches. On the basis of the above, Chapter finite element analysis of photonic crystal fiber, the basic characteristics of the main mode and the mode field distribution, and has been published and recognized by international peers, which verifies this article model and method of the study shows that the finite element method to analyze the efficiency of photonic crystal fiber, provides another route for the study of photonic crystal fiber. Chapter VI demonstrates the need for time-domain finite element beam propagation method (FETD-BPM), based on the slowly varying envelope approximation derivation and description of the single-mode fiber transmission Lightwave 3D-FETD-BPM equation, and deal with temporal and spatial discretization of the equation, and to lay the foundation for further in-depth study of the various types of complex structure of an optical waveguide.