Arbitrary Zero-Index Wave Transport Enabled by Reconfigurable Photonic Crystals

Abstract Dirac-like photonic crystals (PC) have garnered significant attention due to their zero-refractive-index (ZI) properties; however, Dirac cones are susceptible to disorder and perturbations, hindering the practical realization of uniform fields and zero-phase-difference propagation. This work demonstrates a stable coexisting state of bound states in the continuum (BIC) and ZI, exhibiting rotational robustness and low radiative loss. In this proposed system, rotational disorder acts as a random perturbation potential; remarkably, ZI transmission remains robust due to scattering averaging effects. The effective Dirac frequency is given by the statistical probability distribution function of rotation angles, effectively converting disorder from a hindrance into a tunable degree of freedom. Leveraging these properties, we demonstrate a reconfigurable wave distributor capable of path-independent transport, where the number and position of output ports can be controlled on demand. Furthermore, the platform’s reconfigurability enables devices with unconventional boundaries that are robust to variations in incident waves. By enabling multifrequency compatibility and programmability at a Dirac point, we introduce a new paradigm for dynamically reconfigurable photonic architectures and advance optical communication, computing, and interconnection.