本論文主要在探討如何藉著將光子晶體波導與各種不同型態之點缺陷耦合以產生濾波效果。藉由觀察不同結構之穿透率頻譜圖將可設計最佳化的寬頻濾波器。 論文之分析步驟如下。首先以平面波展開法求出所欲分析光子晶體之頻帶，以找出帶隙，接下來導入缺陷態，再使用多重散射法求出帶有缺陷光子晶體結構的頻率－穿透率圖及場圖，進而由頻率－穿透率圖可求出點缺陷共振腔的Q factor，最後針對模擬的結果分析各結構的場圖狀況、缺陷所造成頻率－穿透率圖的變化以及共振腔Q factor等等，以找出最佳的設計。 而思考邏輯基本上依循著Plan-Do-Check-Act的cycle持續對寬頻濾波器的濾波效果做改善。 In this thesis we study the problem of how to design a wideband band-pass filter by using waveguide-defect coupling mechanism. The filter consists of a photonic crystal waveguide and several point defects. By observing the transmission-frequency curves of various configurations , we can modify the structure and finally find the optimized design of the filter. The analytic procedure is as follows: 1. Using plane-wave expansion method to determine the photonic crystal structure’s band gap, which is the working frequency region for the defects and the waveguide. 2. Using multiple scattering method to determine the field pattern and transmission-frequency diagram for photonic structures with defects. We can calculate the cavity’s Q factor according to transmission-frequency diagram. 3. Finally, we analyze the simulation results of field patterns, the transmission-frequency diagram, and the relations between the defect sizes and transmission-frequency diagram and cavity’s Q factor to find the optimal design. Basically, we follow the “Plan-Do-Check-Act” PDCA cycle to contineously improve the performance of the photonic band-pass filter.
