[1] T. Ozawa et al. Topological photonics. Rev. Mod. Phys., 91, 015006(2019).
[4] H. Hodaei et al. Parity-time–symmetric microring lasers. Science, 346, 975-978(2014).
[13] K. Sakoda. Optical Properties of Photonic Crystals(2005).
[14] N. W. Ashcroft, N. D. Mermin. Solid State Physics(1976).