Generation of Weyl points in coupled optical microdisk-resonator arrays via external modulation

We theoretically propose a scheme to produce Weyl points in two-dimensional (2D) optical microdisk-resonator arrays, which undergo a dynamical modulation with temporal periodicity. By mapping the set of modes supported by each resonator to a synthetic frequency dimension, the 2D lattice is equivalent to a three-dimensional (3D) time-independent lattice. We show that, by breaking the inversion symmetry (I symmetry) or introducing artificial gauge fields, Weyl points can be formed, leading to anomalous topological edge states and Fermi arcs. This approach may provide a way to design robust topological photonic devices on chips and future applications for integrated photonics.