Optics and Photonics Society of Iran

Simulation of Au:Ag heterodimers was carried out in LUMERICAL software using FDTD solver. Localized surface plasmon resonance (LSPR) was calculated for Au nanoparticles and compared with LSPR and Fano resonance for Au:Ag heterodimers. The Fano resonance peak was optimized by changing the nanoparticle size and the distances between the nanoparticles. The highest intensity of the Fano resonance peak was achieved when the radius ratio of Au: Ag was 4:1, and the distance was 9 nm. The outcomes reveal that by a slight changing the refractive index of a substance in biosensors, the Fano resonance peak has higher sensitivity than the localized surface plasmon resonance peak.