Abnormal Frequency Scaling of the Topological Bulk States in a Three‐Layer Heterostructure Cavity with Dirac Photonic Crystals

Abstract Topological photonic crystal (PC) plays a vital role in optical cavities, and the resulting nontrivival optical properties promote the development of novel topological lasers. However, there is still a lack of effective means to precisely control the oscillating frequency. In this work, we investigate an abnormal frequency scaling of the topological bulk states in a nontrivial‐Dirac‐trivial cavity. The resonant frequencies of both dipole and quadrupole modes in the inner domain can be linearly varied by modulating the domain size of the intermediate Dirac PC, while the frequency scaling coefficients can be altered by the Dirac point frequency position. Furthermore, the frequency scaling principle also applies to the suspended PC membrane and generates consistent far‐field emission profiles. This work provides a facile strategy for resonant frequency regulation of topological cavities, and paves the way for the development of multi‐channel optical filters and high‐performance semiconductor laser array.