Anomalous dispersion relations by symmetry breaking in axially uniform waveguides
Anomalous dispersion relations by symmetry breaking in axially uniform waveguides
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DOI：
10.1103/physrevlett.92.063903
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发表时间：
2004-02-13
影响因子：
8.6
通讯作者：
Joannopoulos, JD
中科院分区：
文献类型：
--
作者：
Ibanescu, M;Johnson, SG;Joannopoulos, JD
我们证明了任意截面的轴向均匀波导的模可以由于两个模之间的强排斥而具有反常色散关系。当轴向波矢量k为0时，两种模式具有不同的TE/TM对称性，因此可以任意接近偶然的频率简并。对于非零k，对称性被打破，导致模式排斥。当模式足够接近时，这种排斥会导致不寻常的特征，例如非常平坦的色散关系，向后波，非零k的零群速度，状态密度的非典型发散，以及k=0时的非零群速度。
We show that modes of axially uniform waveguides of arbitrary cross section can be made to have anomalous dispersion relations resulting from strong repulsion between two modes. When the axial wave vector k is 0, the two modes have different TE/TM symmetry and thus can be brought arbitrarily close to an accidental frequency degeneracy. For nonzero k, the symmetry is broken causing the modes to repel. When the modes are sufficiently close together this repulsion leads to unusual features such as extremely flattened dispersion relations, backward waves, zero group velocity for nonzero k, atypical divergence of the density of states, and nonzero group velocity at k=0.