Surface Plasmon Resonance Sensor With High Sensitivity and Wide Dynamic Range

Surface plasmon resonance sensor with phase and angular interrogations is proposed in this paper to achieve high sensitivity in a wide dynamic range. The phase interrogation is achieved by Michelson interferometer and the angular interrogation is achieved by rotator. The sensitivity of 7.2×10
^-7
RIU/0.1° (refractive index unit) and the figure of merit of 316 RIU-1 in a dynamic range from 1 to 1.4 RIU are obtained experimentally. The dynamic range of the sensor covers almost all the gas samples, biological samples, and most of liquid samples, so it can be used as gas sensor, liquid sensor, or biosensor. If the prism with high refractive index (i.e., n >1.9 RIU) is adopted then the dynamic range of the sensor can be higher than 0.6 RIU in principle.