基于直径为7.2 μm的微盘谐振腔器件, 分别引入对称缺陷和非对称缺陷, 利用时域有限差分法研究缺陷位置和尺寸对各自微盘谐振腔各阶模式的影响.研究表明: 随着缺陷半径增大, 各阶谐振模式向短波长移动并且由高到低逐级受到抑制.在对称缺陷腔、非对称缺陷腔中内嵌一个微盘, 构成内嵌型双微盘谐振腔, 并优化缺陷腔、内嵌微盘尺寸及位置, 可实现1 128 nm、1 109 nm波长的稳定单模谐振.该内嵌型双微盘谐振腔微盘模式简单, 实现了谐振模式的简化, 具有广泛的应用前景.

Mode radiation loss for microdisk resonators with pedestals is investigated by three-dimensional (3D) finite-difference time-domain (FDTD) technique. For the microdisk with a radius of 1 \mu m, a thickness of 0.2 \mu m, and a refractive index of 3.4, on a pedestal with a refractive index of 3.17, the mode quality (Q) factor of the whispering-gallery mode (WGM) quasi-TE7;1 first increases with the increase of the radius of the pedestal, and then quickly decreases as the radius is larger than 0.75 \mu m. The mode radiation loss is mainly the vertical radiation loss induced by the mode coupling between the WGM and vertical radiation mode in the pedestal, instead of the scattering loss around the perimeter of the round pedestal. The WGM can keep the high Q factor when the mode coupling is forbidden.