To demonstrate the existence of singular parity-time symmetry (PT-symmetry) broken point in optics system, we designed a one-dimensional PT symmetric structure including N unit-cell with loss and gain materials in half. We performed an analytical deduction to obtain the transmittance and reflectance of the structure basing on Maxwell’s equations. We found that with the exact structure unit-cell number and the imaginary part of refraction index, the transmittance and reflectance are both close to infinite. Such strict condition is called the singular point in this study. At the singular point position, both the transmission and reflection are direction-independent. Away from the singular point, the transmittance and reflectance become finite. In light of classical wave optics, the single unit and total structure both become the resonance units. The infinite transmittance and reflectance result from the resonance matching of single unit and total structure. In light of quantum theory, the singular point corresponds to the single eigenvalue of electromagnetic scattering matrix. The infinite transmittance and reflectance mean a huge energy transformation from pumping source to light waves. Numerical calculation and software simulation both demonstrate the result.

设计了一种嵌入磁性材料微腔的可调制的PT对称结构。通过传输矩阵法计算结构的传输谱,研究了磁微腔共振对PT对称结构的调制效应,得到一种可被入射角度方向和大小双重调制的增强的非互易带边模式,调制结果是带边模式在左右带边的转换。磁场大小的增加会导致带边模式向高频移动,磁场方向的变化也会引起带边模式在左右带边的转换。