An Ag/SiO2/Ag sandwich delta nanostar with three sharp angles (30 degrees) is proposed. The extinction efficiency property with a variation in environment refractive index has been investigated in detail by the finite difference time domain method. The refractive index response sensitivity is 482.67 nm/RIU. And the correlations between resonance wavelengths and thickness of the dielectric layer are also established. It reveals that as the thickness increases, the peak wavelength turns to red shift, and a tunable resonance wavelength is achieved through the thickness adjusting of the SiO2 layer. The maximum of the electric field enhancement is 833.776 with the thickness of the dielectric layer h = 40 nm. Moreover, the influence of the vertex truncation on the extinction spectra and the refractive index sensitivity has also been analyzed. (C) 2014 Optical Society of America
1.Chinese Acad Sci, Inst Opt & Elect, State Key Lab Opt Technol Nanofabricat & Microeng, Chengdu 610209, Peoples R China 2.Chinese Acad Sci, Grad Univ, Beijing 100039, Peoples R China 3.Columbia Univ, Dept Mech Engn, New York, NY 10027 USA
Luo, J.,Qiu, C. K.,Wang, W. M.,et al. Plasmon hybridization in composite nanostructures with tunable resonances and vertex truncation analysis[J]. APPLIED OPTICS,2014,53(16):3528-3532.