In order to study the exceptional point (EP) properties in the photonic crystal waveguide, we construct the two-dimensional photonic crystal waveguide with the parity–time symmetry configuration. With the calculation of the eigen frequencies, the evolution of the waveguide mode bands discloses two EP-induced flat bands. The transmittance and reflectance at the two flat bands show a huge amplification property and the structure become a waveguide laser. The waveguide lasing is due to the common properties of the EP and the flat band. The results have been demonstrated by the transmission spectra, Poynting vector distribution and simulations of field propagation.

中文翻译：

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例外点诱导平带和波导激光器

为了研究光子晶体波导中的异常点（EP）特性，我们构建了具有奇偶时间对称配置的二维光子晶体波导。通过计算本征频率，波导模式带的演变揭示了两个 EP 诱导的平坦带。两个平带处的透射率和反射率表现出巨大的放大特性，结构成为波导激光器。波导激光是由于 EP 和平带的共同特性。结果已通过透射光谱、坡印廷矢量分布和场传播模拟得到证实。