本論文主要討論漸變折射率共振腔，具有良好的Q值系統，利用等效折射率的概念，將漸變折射率共振腔做三大類的等效設計，分別為r方向法、θ方向法與扇形面積法。在這三種等效中，我們使用Comsol模擬軟體都得到良好的Q值，其中在θ方向法中，我們所得到的Q值高達 。 另外，我們在θ方向法的設計結構，由色散關係進一步分析，電磁波在共振腔內產生的聲頻支模態，而其電場圖由行進波轉變成駐波形式，同時也得到結構層數與可容許最大波長數量關係。We use gradient effective index structures designing high-Q photonic crystal cavities (2D). And the gradient index of refraction is the parabolic distribution, it also has high-Q in the system. We calculated effective index on the r and θ direction, and the structures are formed by inserting two materials of different refractive indices ( n1=3.31 ,n2=1 ), keeping the local averaged index varying gradually along the r and θ direction. For E-polarized modes, the θ direction structure has the highest Q?6.85x109 . ( All the simulations of field patterns in this thesis are implemented by using COMSOL MultiphysicsTM 3.5a.)
