Fabrication and Applications of Microfiber Coil Resonators with Enhanced Quality Factors by Increasing Coil Numbers

在本論文中，我們建造了一個品質因素達到470,000的微光纖線圈共振腔。 實驗以及模擬的結果都指出當微光纖線圈共振腔纏繞的圈數增加時，即使是線圈中每一圈的間距並不全都相同，只要能將圈與圈的間距控制在1.5 μm的範圍之內，共振腔平均的品質因素將會隨著圈數增加而增大。比較先前的研究結果，多圈的微光纖線圈共振腔提供了另一個製作高品質因素的微光纖共振腔的新選擇。 此外，本論文也對微光纖線圈共振腔在光纖陀螺儀的應用以及折射率感測的應用上進行可行性分析。在光纖陀螺儀方面，我們證實了其最小可感測轉速與共振腔的品質因素是正相關的。若將我們的微光線線圈共振腔應用在光纖陀螺儀的系統上，我們預期可以最小可量測轉速理論可達0.1°/s。在折射率感測方面，模擬的結果指出雖然提升微光纖線圈共振腔的品質因素對提升折射率的靈敏度是沒有幫助的，但是可以提升可量測的折射率變化的極限，對於一個品質因素達到470,000的微光纖線圈共振腔，我們估計其可量測的最小折射率變化為3×10-6 RIU。Microfiber coil resonators (MCRs) with quality factors as high as ~470,000 were fabricated and characterized. Both simulated and experimental results showed that the average quality factor of the resonant dips increased with the number of rings, providing a proof of the dependence of increasing quality factor upon the number of rings even when the gaps among adjacent rings were not strictly uniform but need to be controlled within 1.5 μm. Compared with the previous reports, a multi-ring MCR can thus offer a new method of obtaining a microfiber resonator with high quality factor. Furthermore, the feasibility studied of both the MCR-based gyroscope and the refractive index sensors were also studied. For our MCR-based gyroscope, we proved the sensitivity is related to the quality factor of MCR and estimated the minimum detectable rotation rate is about 0.1°/s. For the MCR-based refractive index sensor, high quality factor of an MCR could enhance the detection limit. For the MCR with quality factor of 470,000, we estimated its detection limit was about 3×10-6 RIU