Cheng Pi-Ju, Tien Chung-Hao, Chang Shu-Wei
Opt Express. 2015 Apr 20;23(8):10327-40. doi: 10.1364/OE.23.010327.
We show that the propagating modes in a strongly-guided chiral one-way photonic crystal are not backscattering-immune even though they are indeed insensitive to many kinds of scatters. Since these modes are not protected by the nonreciprocity, the backscattering does occur under certain circumstances. We use a perturbative method to derive criteria for the prominent backscattering in such chiral structures. From both our theory and numerical examinations, we find that the amount of backscattering critically depends on the symmetry of scatters. Additionally, for these chiral photonic modes, disturbances at the most intense parts of field profiles do not necessarily lead to the most effective backscattering.
我们表明，在强引导的手性单向光子晶体中的传播模式并非对后向散射免疫，尽管它们确实对多种散射不敏感。由于这些模式不受非互易性保护，在某些情况下确实会发生后向散射。我们使用微扰方法来推导此类手性结构中显著后向散射的判据。从我们的理论和数值研究中，我们发现后向散射的量关键取决于散射的对称性。此外，对于这些手性光子模式，场分布最强烈部分的扰动不一定会导致最有效的后向散射。
