本文介紹了一種完全基於有限元方法的多層介質衍射光栅（MDGs）的特性和評估方法，該方法是工程領域的一種重要而高效的工具。本研究的目的是建立多層介質反射光栅高效率的要求，以滿足規定的效能標準。採用多參數計算方法對不同形狀光栅的繞射效率和電場分佈進行了評估。成功地將電場分佈應用於各種類型的衍射光栅形狀，從光栅形狀和入射光參數兩方面確定了最佳的衍射光栅參數。 結果表明，光栅形狀對兩種偏振態的繞射效率都有影響。結果還表明，數值計算的COMSOL是預測MDGs繞射效率的合適工具。提出了一種基於參數掃描的高繞射效率光栅MDGs結構。結果表明，通過改變多層膜結構，提高了MDGs的繞射效率。 利用COMSOL和Essential Macleod，提出了一種組合有限元法(FEM)和薄膜優化方法。 ;This thesis presents the work on the characterization and evaluation of a MDGs based wholly on finite element method, which acts as an important and efficiency tool in engineer field. The aim of the study was to establish requirements for the high efficiency of multilayer dielectric reflection grating to satisfy stated performance criteria. Several parameter calculations were employed to assess diffraction efficiency and electric field distribution of various grating shapes. Electric field distribution was successfully employed for various types of diffraction grating shapes to determine the optimal diffraction grating parameters in terms of grating shapes and incident light parameters. The results obtained have demonstrated that gratings shapes affect the diffraction efficiencies for both polarization state. The results also showed that the numerical COMSOL is a suitable tool for the prediction of diffraction efficiency of MDGs. A MDGs structure is proposed for the high diffraction efficiency grating based on parameter sweeping using COMSOL Multiphysics. The outcomes show that by changing multilayer structure, the diffraction efficiency of MDGs is improved. A combined Finite Element Method FEM and thin films optimization have been developed using COMSOL and Essential Macleod.
