本論文探討錐狀光纖與微米球共振腔之耦合，並評估藉此機制實現積體化全光開關及感測器元件之應用。
實驗上我們選擇激發與探測 (pump and probe) 架構設計光路。藉由光學柯爾效應我們觀察到微米小球隨著pump光源強度不同而產生折射率微幅變化，進而使probe光所激發的耳語廊模場對應的共振波長發生紅移使穿透率發生變化。藉由此現象應用於全光開關其消光比為1.335dB，在開關對比度上尚有改善空間。但在感測器應用上，靈敏度可達1050nm/RIU，以目前研究來說，算是不錯的成果。

In this thesis, we investigate the optical coupling between the tapered fiber coupler and microsphere resonator. The overall concept exploits are ultra-high Q and small modal volume in the resonator, leading to the significant decrease of the threshold power of nonlinearity. Using these advantages, we may broaden the applications to all optical switching and environmental sensors.
Experimentally pump-probe method was utilized in our setup. The modulation of the refractive index of the microsphere was observed under various input powers, and the WGM resonant wavelength shifted correspondingly. The extinction ratio is estimated to be 1.335dB between on/off states, and further improvement is no doubt necessary. We have lots of improvement. On the other hand, however, the sensitivity of this device is 1050nm/RIU, which is comparable to current integrated optical sensors. Further improvement of the sensitivity can be achieved by using a smaller resonator.

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