Grating surface plasmon resonance sensor: angular sensitivity, metal oxidization effect of Al-based device in optimal structure

摘要

We present the wavelength (lambda)-independent ultimate and maximum angular sensitivity of a grating surface plasmon resonance sensor, as long as the grating of metal has much higher permittivity than analyte (n(a)(2)). For 1.32 <= n(a) <= 1.36, the maximum angular sensitivity reaches 493.7 (535.9)degrees/RIU by the single (double)-dip method. The real Al-based sensor in an optimal structure for a high figure of merit exhibits higher sensitivity but narrower reflection dip when working at a longer wavelength, and the real sensitivity increases from 292.5 (344.5) to 338.0 (396.3)degrees/RIU at respective lambda = 0.85 and 1.55 mu m before the metal oxidation. After the oxidization, the sensitivity is degraded by <= 3.2% (2.8%), and the detection error of delta n(a) <= 1.3e - 3 (1.1e - 3) is introduced to the sensor working at near-infrared wavelengths of interest. (C) 2015 Optical Society of America