Topological Guidance in a Quasiperiodically Modulated Coupled Multicore Optical Fiber

We propose an all-solid multi-core fiber design where high-index cores are arranged in a circular fashion and quasiperiodically coupled with each other. This unique geometry enables the transfer of light, from the localized state in the first core to the localized state in the last core through formation of mixed states of light. This light transfer mechanism depends on the phase of quasiperiodic modulation and remains unaltered regardless of variations in the number of cores. The observed phenomenon is as an evidence of adiabatic pumping in the quasiperiodically modulated structure, supporting a topological supermode of the fiber within this coupled multi-core configuration. Further, we examine the impact of off-diagonal disorder and wavelength variations on the states of this topological fiber mode. This specialized topological fiber exhibits potential for robust beam delivery which is immune to any perturbation and can serve as a candidate for further exploring nonlinear effects on the topological mode in the fiber geometry for potential application including robust fiber-quantum networks.