Refractive index sensor based on surface-plasmon interference


Wu, X., Zhang, J., Chen, J., Zhao, C. & Gong, Q. Refractive index sensor based on surface-plasmon interference. OPTICS LETTERS 34, 392-394 (2009).


We propose a refractive index sensor based on the interference of two surface-plasmon waves on both surfaces of a gold film with a two-slit structure. The phase of the interference was solved, and the dispersion relation of the real part of Au dielectric function was considered. The sensor was performed with NaCl-H(2)O solutions of different concentrations and exhibited a linear response and a high sensitivity of 4547 nm/RIU (refractive index unit) to the refractive index change. (c) 2009 Optical Society of America