Observation of Selective Light‐Trapping in Half‐Dislocation Dual‐Photonic Crystal Microcavity

Abstract Topological photonic crystal (PhC) microcavities, renowned for their exotic characteristics like high‐quality factors (Q ‐ factors) and near‐diffraction‐limited mode volume, hold tremendous promise for applications in quantum information, laser technology, and integrated photonic chips. However, achieving flexible tunability and asymmetry in multi‐cavity systems remains a challenge. In this work, an innovative real‐momentum topological dual‐optical microcavity system is proposed with two degenerated zero modes. Quite different from the proposed multi‐microcavity systems, these two modes exhibit the same phase and are represented as the even mode in one cavity under both dual‐cavity coupling and time‐reversal symmetry ( T ‐symmetry) breaking, while in the other cavity they display opposite phases and are characterized as the odd modes, which results in only one cavity surviving after superposition. By dynamically manipulating the orientation of the external magnetic field, electric field localization can be selectively activated in a designated microcavity. Both simulations and experimental measurements verify the symmetry of our model. As a promising application, an asymmetric radiation antenna is further proposed, which paves a new avenue for flexible topological PhC devices.