Giant Goos-Hänchen shift by steering the transition from local to nonlocal plasmonic resonances

Achieving giant Goos-Hänchen (GH) shifts in plasmonic structures is crucial for photonic applications, including information storage and ultrasensitive sensing. However, high-loss plasmonic structures inhibit the realization of high quality (Q) factor resonances. In this Letter, leveraging the transition from local to nonlocal plasmonic (NP) resonances, we demonstrate giant GH shifts reaching values of ~10³ wavelengths, which are assisted by NP resonances with high Q factors. Furthermore, we propose an ultrasensitive biosensor based on the enhanced GH shifts by NP resonances with high Q factors. Our work reveals the tremendous potential of NP resonances for various applications in plasmonic structures.