微環型共振器(Micro Ring Resonator, MRR)之運作原理為，根據其設計之環型波導周長，波導本身之等效折射率等條件，我們可觀察到將會有特定波長之光會被偶合至環型共振器內部，造成在微環型共振器穿透端之光譜上，會觀測到光譜以一特定週期出現衰減，同時在抓取端之光譜可觀察到光以同樣週期出現。傳統型微環型共振器透過此特性，主要為觀察共振波長的改變，後續再以此為基礎衍伸出各種不同的觀測方式如線寬變化或共振波長之週期變化等不同感測系統。並且以其體積小、靈敏度高、量測速度快等特性作為量測上的優點而被廣泛討論。
本論文旨在探討利用Ring down之現象做為感測以及傳統型微環型感測器與雙環型共振器耦合MZI (Mach-Zehnder Interferometer)兩種不同架構，我們藉由觀測不同波導外部折射率所造成光譜的變化，再進一步由傅立葉轉換得知時間域之訊號，利用觀察相位變化得以感測等校折射率之改變，由此可對待測物進行感測。在一般使用OSA觀察共振波長變化上若假設本實驗室之儀器的解析度10pm為感測極限，可得出LOD(limit of detection)大致約為5×〖10〗^(-4)RIU，而若使用低同調光纖光學干涉(OFLCI)以本實驗室之步進馬達20nm為感測極限則LOD約為7.01×〖10〗^(-8)RIU，計算上進一步發現在雙環型共振器耦合MZI架構上，除了因為可以選擇對複數Ring down做相位計算，感測靈敏度比起傳統型微環型感測器更好之外，對於MZI上的相位變化也是不敏感的。
我們在計算上藉由加入Fano共振效果測試對於感測靈敏度之影響，Fano共振是一可以藉由相位差產生的現象，我們可以藉此現象觀察相位變化的程度，當我們在MZI上對其中一微環型共振器產生Fano共振時，以商業軟體計算發現我們的架構靈敏度對於相位變化不敏感，無論Fano共振程度皆不會影響到我們觀測系統的相位變化，也因此不影響系統的系統LOD。
此外在我們將藉由實驗對一傳統微環型共振器晶片觀察在不同波導折射率之相位變化，以此來佐證我們的量測方式可被實際應用於實作，並藉由單微環型共振器實驗之感測靈敏度和我們理論設計之LOD做出比較。

The waveguide-based microring resonator (MRR) is operated through the ring perimeter, refractive index, optical coupler, and propagation loss. The light injected into the MRR results in a particular period in the through port. At the same time, the exact wavelengths will appear with the same period at the drop port. A conventional MRR is mainly utilized to observe the change of resonant wavelengths through this feature. Then it is also used as a basis for several detection methods such as line width variation or periodical change of resonant wavelengths and other different sensing systems. It is widely discussed for its small size, high sensitivity, and fast measurement speed.
This thesis aims to explore the ring down phenomenon for sensing and two different structures: the conventional micro-ring sensor and the dual-ring resonator coupled Mach-Zehnder Interferometer (MZI). The output spectrum is moving with the refractive index variation. Further, the signal in the time domain will be followed by Fourier transform (FT) and forms the ring-down phenomena. If we use OSA to observe the resonance wavelength change, assuming that the resolution of this laboratory's instrument is 10 pm as the sensing limit, the LOD (limit of detection)can be approximately 5×〖10〗^(-4)RIU , and if we use the optical fiber low coherence interferometry (OFLCI) with the laboratory's step motor of 20 nm as the sensing limit, the LOD is approximately7.01×〖10〗^(-8)RIU. The theoretical calculation further reveals that the dual-ring resonator-coupled MZI structure has better sensing sensitivity than conventional micro-ring sensors because it can choose to do phase calculation for multiple Ring down. Also, it is insensitive to phase changes on the MZI.
Fano and Non-Fano resonances could be generated by the phase difference of the dual-ring resonator micro-ring coupled MZI. These two resonances theoretically demonstrate the same high sensitivity, which means that the dual-ring resonator coupled MZI performs phase insensitive resonance biosensing.
In addition, the phase of a conventional micro-ring resonator chip is experimentally manipulated by the applied voltage to change the refractive index of a waveguide for the sensitivity study. The new proposed windowed FT can adequately be utilized to illustrate the sensing sensitivity.

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