Improving Surface Plasmon Detection in Gold Nanostructures Using a Multi‐Polarization Spectral Integration Method

A multi-polarization spectral integration method to increase the refractive index detection limit of gold nanostructures is presented. For a dual-period nanogrid structure, the proposed method increased signal-to-noise ratio and refractive index detection limit about 8 times larger than the simple intensity method. The nanogrid achieves a detection limit of 1.92 × 10−6 refractive index unit when the intensity stability is 0.2%.