本論文中以耦合波理論(coupled mode theory)與環型共振腔模型出發，設計一有較長耦合長度的滑輪式環形共振腔(pulley type ring resonator)，並以有限時域差分法(finite-difference time-domain methods, FDTD)模擬電磁波在共振腔中傳播情形，研究單一載波波導、add & drop system與滑輪式環型共振腔的光侷限能力。發現滑輪式環型共振腔具有較高的Q值，也就是有較好的光侷限能力，之後以光能量偵測器以及波印庭向量去分析共振腔之光損耗，找到光損耗最大位置，並將光損耗分為來自外圍波導與環的模態不匹配，能量不完全耦合之耦合損耗以及能量在波導傳播時的彎曲損耗。最後模擬一理想環型共振腔，其能量由外圍波導完全耦合至環內，其Q值可以提高近十倍。In this study, the coupled mode theory is used to develop the pulley type ring resonator, in which the coupling length is longer than that of the conventional ring resonators. The finite-difference time-domain methods (FDTD) are used to solve the Maxwell’s equations in time domain. The electromagnetic field distribution (EMF) can be obtained by the FDTD method inside and outside the ring resonator. We analyzed the EMF distributions to observe the loss of the single waveguide ring resonator, add & drop system, and pulley type ring resonator. The result shows that the quality factor of the pulley type ring resonator is higher than the quality factor of other types. The Poynting vector and the power distribution of the pulley-type ring resonator have also been calculated. We investigated the originality of the loss. This can help to optimize the Q factor of the ring resonators.
