High-sensitivity Optical Sensor Based on Surface Plasmon Resonance Enhanced Goos-Hänchen shift

A new optical sensor based on surface plasmon resonance (SPR) enhanced Goos-Hanchen(GH) shift is presented. Compared with the traditional SPR techniques, the new method provides higher sensitivity to sensor system. Theoretical simulations show the refractive index (RI) detection sensitivity of the SPR sensor based on the GH shift measurement has a strong dependence on the thickness of the metal film. When the optimal thickness of the metal film is selected, the RI resolution of the SPR sensor is predicted to be 2.2 times 10^-7 refractive index units (RIU). Furthermore, it is found that the incidence angle can be used as a parameter to adjust operating range of the sensor to different refractive index ranges.