Phase detection model and method for SPR effect modulated by metallic thickness

摘要

A mathematic model based on surface plasmon resonance (SPR) effect is presented to measure the nano metallic film thickness with the coupling device of Kretschmann configuration composed of K9 prism-gold film-air. Four modulation modes of SPR method, such as intensity, phase, wavelength and angle, are numerically analyzed. Their detection principles, the measurement range and sensitivity of different modulation type sensors are discussed. The simulation results show that the SPR intensity detection method has the highest measurement range and the SPR phase detection method has the highest sensitivity. In practical applications, not only the measurement range and sensitivity, but the optical signal processing mode, experiment devices, the complexity of the algorithm and cost factors should be considered to research and develop the appropriate thin metallic film's thickness measurement SPR sensor with higher sensitivity and stability.