Sensitivity enhancement of surface plasmon resonance sensor based on wavelength and angular combined modulations

We propose an optimizing method to improve the sensitivity of bimetallic film surface plasmon resonance (SPR) sensor based on wavelength and angular combined modulations. The incident angle and thickness of transducing layer are optimized in terms of a variation range of refractive index, instead of one given value of refractive index. This method can reduce the SPR dip for the whole variation range of refractive index and maintain high sensitivity simultaneously. The theoretical results show that the highest sensitivity can achieve 22,000 nm/RIU, which is almost twice larger than the results without optimization under the same condition.