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.