Jörg, C.C.JörgVaidya, S.S.VaidyaNoh, J.J.NohCerjan, A.A.CerjanAugustine, S.S.AugustineFreymann, G. vonG. vonFreymannRechtsman, M.C.M.C.Rechtsman2022-05-062022-05-062022https://publica.fraunhofer.de/handle/publica/41644510.1002/lpor.202100452Weyl points are point degeneracies that occur in momentum space of 3D periodic materials and are associated with a quantized topological charge. Here, the splitting of a quadratic (charge-2) Weyl point into two linear (charge-1) Weyl points in a 3D micro-printed photonic crystal is observed experimentally via Fourier-transform infrared spectroscopy. Using a theoretical analysis rooted in symmetry arguments, it is shown that this splitting occurs along high-symmetry directions in the Brillouin zone. This micro-scale observation and control of Weyl points is important for realizing robust topological devices in the near-infrared.en003621006519Observation of Quadratic (Charge-2) Weyl Point Splitting in Near-Infrared Photonic Crystalsjournal article