[21p-A101-1~16] 3.10 Photonic structures and phenomena (formerly 3.11)

▲ [21p-A101-10] Topological Wave Propagation in 3D Woodpile Photonic Crystal

〇ThanhHuyen Phan¹, Shun Takahashi², Satoshi Iwamoto³, Katsunori Wakabayashi¹ (1.Kwansei Gakuin Univ., 2.Kyoto Inst. of Technology, 3.The Univ. of Tokyo)

Keywords:topological photonic crystals

The topological phases of matter, which were first discovered in electronic systems, have significantly extended our understanding about condense matter physics. The main property of d-dimensional topological insulators is the topological protected (d-1)-dimensional boundary states which are robust against the defect modes and perturbations. Recently, a new class of topological insulators called higher order topological insulators has extended the conventional bulk-edge correspondence theory and increase the motivation of finding new promising topological materials.Applying this theory to photonic systems, the second order topological states as corner states has been theoretically and experimentally observed in two-dimensional photonic crystals. In this research, we theoretically design a three-dimensional photonic crystal structure by arranging dielectric blocks in diamond cubic lattice, named woodpile photonic crystals. Finite element method is used to evaluate the photonic band structure. Beside the topological surface states at four side-surfaces, the propagation one-dimensional hinge states are also observed along two hinges. Since the multidimensional topological states are found at different frequencies and in a gap of bulk states, our results may support for the devices that can manipulate the propagation of electromagnetic wave in multiple dimensions.