Visualization of unidirectional optical waveguide using topological   photonic crystals made of dielectric material
  The introduction of topology unravels a new chapter of physics. Topological systems provide unique edge/interfacial quantum states which are expected to contribute to the development of novel spintronics and open the door to robust quantum computation. Optical systems can also benefit from topology. Engineering locally in real space a honeycomb photonic crystal with double Dirac cone in its photonic dispersion, topology transition in photonic band structure is induced and a pseudospin unidirectional optical channel is created and demonstrated by the backscattering immune electromagnetic transportation. The topological photonic crystal made of dielectric material can pave the road towards steering light propagations and contribute to novel communication technology. 
Yuting Yang, Yun Fei Xu, Tao Xu, Hai-Xiao Wang, Jian-Hua Jiang, Xiao   Hu and Zhi Hong Hang
physics.optics