High-Sensitivity Sensor Based on Surface Plasmon Resonance Enhanced Lateral Optical Beam Displacements

We present a new optical sensor based on surface plasmon resonance (SPR) enhanced lateral optical beam displacements. Compared with the traditional SPR methods, the new method provides higher sensitivity to the sensor system. Theoretical simulations show that the refractive index (RI) detection sensitivity of the SPR sensor based on the displacement 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 2.2×10^-7 refractive index units (RIU). Furthermore, it is found that the incidence angle can be used as a parameter to adjust the operating range of the sensor to different refractive index ranges.