Observation of Quadratic (Charge‐2) Weyl Point Splitting in Near‐Infrared Photonic Crystals

Weyl points are point degeneracies that occur in momentum space of periodic materials, and associated with a quantized topological charge. We experimentally observe 3D micro-printed photonic crystal charge-2 can be split into two charge-1 as the protecting symmetry original is broken. Moreover, we use theoretical analysis to confirm where move within Brillouin zone strength breaking increases, it experiments using Fourier-transform infrared spectrometry. This micro-scale observation control important for realizing robust devices near-infrared.