摘要
Photonic crystals offer a platform for manipulating light at the mesoscopic scale owing to the unique photonic bandgap properties originating from spatially periodic dielectric distributions.Not only various integrated photonic devices have been realized based on photonic crystals,such as photonic crystal laser and logic devices,but also many physical effects including negative refractive and optical cloak have been realized in photonic crystals.Based on the photonic band structure,topological photonics has been an emerging research hotspot nowadays.Topological photonics provide two new modulation degrees of freedom,i.e.,topological state degrees of freedom and energy valley degrees of freedom.It can be expected that topological photonics will not only boost the fundamental study of physical effects and phenomena,but also improve the research of high-performance photonic devices.
