Dynamic measurement of an angular Goos-H?nchen shift at a surface plasmon resonance in liquid

We developed a surface plasmon resonance (SPR)-enhanced angular Goos-Hanchen (GH) shift measurement sys-tem capable of tracking small refractive inder changes with high sensitivity in a liquid environment. Our method can be performed in angular interrogation schemes, where we demonstrate a simple zero-finding algorithm to locate the SPR angle instead of the complicated data processing algorithms used in conventional sensors. We also propose a displacement interrogation scheme for dynamic measurement of small refractive inder changes in the sample. The main advantage of our method is the controllability of the measured displacement by standard geometrical optics, allowing measurement sensitivity enhancement without the need to modify the sensor material. (c) 2023 Optica Publishing Group