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 (<i>Q</i>) 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 <i>Q</i> factors. Furthermore, we propose an ultrasensitive biosensor based on the enhanced GH shifts by NP resonances with high <i>Q</i> factors. Our work reveals the tremendous potential of NP resonances for various applications in plasmonic structures.