5 papers
Topological spin defects of light
Haiwen Wang, Charles C. Wojcik, Shanhui Fan
Topological defects are found in a variety of systems, and their existence are robust under perturbations due to their topological nature. Here we introduce a new type of topologic…
Isotropic Topological Second-Order Spatial Differentiator Operating in Transmission Mode
Olivia Y. Long, Cheng Guo, Haiwen Wang +1
Differentiation has widespread applications, particularly in image processing for edge detection. Significant advances have been made in using nanophotonic structures and metamater…
Controllable finite ultra-narrow quality-factor peak in a perturbed Dirac-cone band structure of a photonic crystal slab
Alex Y. Song, Akhil Raj Kumar Kalapala, Ricky Gibson +9
We show that by using a perturbed photonic Dirac-cone, one can realize ultra-narrow and finite Q-factor peak in the wavevector space, with both the peak value and the width separat…
Squeeze free space with nonlocal flat optics
Cheng Guo, Haiwen Wang, Shanhui Fan
There has been substantial interest in miniaturizing optical systems by flat optics. However, one essential optical component, free space, fundamentally cannot be substituted with…
-Symmetric Topological Edge-Gain Effect
Alex Y. Song, Xiao-Qi Sun, Avik Dutt +6
We demonstrate a non-Hermitian topological effect that is characterized by having complex eigenvalues only in the edge states of a topological material, despite the fact that the m…