利用时域有限差分法, 对基于绝缘体上硅(SOI)的微环谐振腔的微环波导宽度对传输性能、Q值的影响进行了理论分析与仿真。研究结果表明, 单模条件下, 波导越宽, Q值越大。仿真优化结果表明微环半径为10μm、微环波导宽度为600nm时, 1.55μm附近的谐振峰的消光比为18.2dB, 计算出Q值约为2.2×105。进一步研究了微环与直波导间距、平板高度对Q值的影响。耦合间距增大时, 由于耦合效率降低, Q值则逐渐提高; 随着平板区厚度的减小, 辐射损耗会越小, 因此Q值增大。研究结果为微环谐振腔的进一步优化和设计提供了参考。

The microring resonator based on the Silicon on Insulator (SOI) is discussed with the algorithm of the Finite Difference Time Domain method (FDTD). The dependence on the microring width of the transmission performance and quality factor is analyzed with simulations. It shows that the wider the waveguide, the higher the quality factor within the single mode regime, it will be a multi-mode waveguide when the waveguide is too wide. When the radius of the microring is 10μm and the microring width is 600nm, the extinction ratio around the wavelength of 1.55μm is about 18.2dB, and the quality factor Q can reach as high as 2.2×105. The larger the gap between the ring and the bus waveguide, the weaker the coupling, thus the higher the quality factor. The quality factor Q will increase sharply with the decreasing pedestal thickness decreases, and the radiation loss decreases too. The works provide some valueable results for further design and optimization of the SOI microring resonator.