本論文中，使用COMSOL模擬軟體，研究耳語迴廊模態（WGM）的碟型及環形共振腔結構和光學特性並依據光學品質因子（FQ）、光學侷限因子（FC）、模態體積（Vm）和Purcell因子（Fp），作為特性改善的指標。首先，模擬結構的尺寸主要為4um的五邊形和六邊形。五角形碟型結構的FQ、FC、Vm和Fp分別為1613、0.96、16.21 和1.268。對於六邊形微碟型結構，它們分別為1221、0.96、19.02 和0.81。由於五邊形結構具有較低的對稱性而展現出比六邊形微碟型結構更好的特性。接著在使用FIB在結構中心位置蝕刻一個圓形孔洞來改善五角形和六邊形結構的特性，以降低高階模態和quasi-WGM。對於五邊形微碟型結構，當中心孔洞的半徑為1.25μm時，FQ、FC、Vm和Fp分別為4331、0.98、12.1 和4.5。對於六邊形微碟型結構，當中心孔洞的半徑為1.75um時，FQ、FC、Vm和Fp分別為1972、0.97、17.1 和1.46。與微碟型結構相比，五邊形環型結構中的FQ、FC和Fp分別增加1.68倍，0.02倍和2.54倍，Vm降低0.25倍。對於六邊形環型結構，與微碟型結構的FQ、FC和Fp分別增加了0.61倍，0.01倍和0.8倍，Vm降低了0.1倍。五邊形微碟型結構相對於六邊形微碟型結構有較好的特性，接著透過FIB挖洞製程形成環型結構，可以顯著的改善光學特性，有效的消除非WGM的模態。

In this thesis, the structure of ring resonator for whisper gallery mode (WGM) and improvement of its optical characteristics were studied by using simulation software, Comsol, according to the optical quality factor (FQ), optical confinement factor (FC), mode volume (Vm) and Purcell factor (Fp) as the basic criteria. First, the WGM in pentagonal and hexagonal structures with side length of 4 um was computed. The FQ, FC, Vm and Fp of pentagonal structure are 1613, 0.96, 16.21 and 1.268, respectively. For the hexagonal structure they are 1221, 0.96, 19.02 and 0.81, respectively. The pentagonal structure shows the better characteristics than hexagonal one because of its lower symmetry. Second, the characteristics of pentagonal and hexagonal structures were improved by caving a hole in the central to reduce the high order mode and quasi WGM. For the central with radius of 1.25 um in pentagonal structure, the better FQ, FC, Vm and Fp are 4331, 0.98, 12.1 and 4.5, respectively. For the one with radius of 1.75 um in hexagonal structure, the better FQ, FC, Vm and Fp are 1972, 0.97, 17.1 and 1.46, respectively. Compared with the one without central hole, the FQ, FC, and Fp in pentagonal structure increases 1.68 times, 0.02 times and 2.54 times, respectively, and the Vm decrease 0.25 times. For the hexagonal structure the FQ, FC, and Fp increases 0.61 times, 0.01 times and 0.8 times, respectively, and the Vm decrease 0.1 times, comparing to the one without central hole. This method shows a significant improvement when using pentagonal structure for WGM lasing. The central hole structure can further improve the performance as well.

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