Generally speaking, our group studies the interesting behaviors of photons in the environment of nanoscopic structures, which can be drastically different from those in macroscopic systems. By studying these new physical effects, we can apply them to invent and design new optoelectronic devices, which we then fabricate and test in the lab. At this point, we focus on the following topics: 

– Topological phases | Recent examples are high-order topological insulators, Floquet Chern insulators of light,  and synthesis of non-Abelian gauge fields. 

– Topological guided resonances | Recent examples are: unidirectional guided resonances, ultra-high-Q guided resonances, and bound states in the continuum 

– Non-Hermitian physics | Here are a few recent projects: observation of bulk Fermi arcs, observation of exceptional ring, and light-matter interaction at exceptional points. 

On the device side, we are most excited about demonstrating fundamentally new devices. A few examples include:  transparent displays, perfect single-side couplers, and low-threshold organic lasers.