Engineering surface lattice resonance of elliptical gold nanodisk array for enhanced strain sensing

We demonstrate an elliptical gold nanodisk array (GNA) for engineering the spectral profile of surface lattice resonance (SLR). The nanodisk’s shape has a great impact on SLR. A small linewidth of 20 nm at an aspect ratio of 1.17 and a large wavelength tuning of 64 nm within 4% strain via different orientations and polarizations is achieved experimentally. The enhanced wavelength response of 6.93 nm per 1% strain variation for elliptical GNA is 2.4 times better than that for general circular GNA. Furthermore, figure of merit of strain sensing for elliptical GNA approaches 5.7 times greater than that for circular GNA.