Chen Xiaogang
Opt Express. 2014 Jun 30;22(13):16363-76. doi: 10.1364/OE.22.016363.
Self rolled-up microtube is a natural device that may couple light vertically out of a planar photonic device. It is instructive to understand the optical resonant modes propagating inside the microtube waveguide. All previous models for the microtube resonant modes ignored the nonconcentric nature of its structure. Conformal transformation was used for the first time to address this issue and to obtain equivalent planar parallel-piped waveguide structure which in turn leads to an approximate analytical solution of the resonant modes of the tube. This work paves the way for accurately calculating the coupling coefficient between the microtube and a planar waveguide. The results calculated using this model matched very well with published experimental data and COMSOL simulation.
自卷式微管是一种天然装置，可将光垂直耦合出平面光子器件。了解在微管波导内传播的光学谐振模式具有指导意义。之前所有关于微管谐振模式的模型都忽略了其结构的非同心性质。首次使用共形变换来解决这个问题，并获得等效的平面平行六面体波导结构，这进而导致了微管谐振模式的近似解析解。这项工作为精确计算微管与平面波导之间的耦合系数铺平了道路。使用该模型计算的结果与已发表的实验数据和COMSOL模拟结果非常吻合。
