Improving the sensing performance of double gold gratings by oblique incident lightElectronic supplementary information (ESI) available: SEM images with tilted (45°) view of S1-S4; simulated spectra of double gold gratings under different polarized light; refractive index sensing of gold grating at normal light with different sucrose aqueous solution concentrations; reflection spectra of gold grating in air using different incidence angles. See DOI: 10.1039/c5nr02660a

• Main Authors: Wu, Feifei, Liu, Lingxiao, Feng, Lei, Xu, Daren, Lu, Nan
• Format: Journal Article
• Language: English
• Published: 23.07.2015
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c5nr02660a

Here we demonstrate a simple method to improve the plasmonic sensing performance of gold gratings. The gratings consist of periodic polymer gratings covered with a gold layer, created by nanoimprint lithography and metal deposition. We investigated the effect of gold thickness and the incident angles on the plasmonic sensing performance. With the optimized gold layer, the full-width at half maximum of this grating was reduced by 60% by using the oblique incident light instead of the normal incident light. A maximum value of the figure of merit at oblique incidence is 12, which is double the one at normal incidence. The refractive index sensing performance of double gold gratings can be improved by using the oblique incident light. And the application of white light instead of polarized light is beneficial to the sensing applications.