Opt Quant Electron DOI 10.1007/s11082-014-0028-7 Location effect on gold nano bi-domes based absorption coefficient Majid Akhlaghi · Farzin Emami · Najmeh Nozhat Received: 15 December 2013 / Accepted: 19 September 2014 © Springer Science+Business Media New York 2014 Abstract Binary particle swarm optimization (BPSO) algorithm was used to generate the binary gold nano bi-domes for getting higher absorption coefficient spectrum. The simula- tion results show that absorption coefficient strongly depends on the localized position of nano particles and non-periodic structures have more appropriate response in term of absorp- tion coefficient. This approach can be useful in optical applications such as solar cell and plasmonic nano antenna. Keywords Plasmonic nano particles · Plasmonic nano antenna · Optimization algorithm · PSO algorithm 1 Introduction Metal nanoparticles have broad applications in electronics (Huang et al. 2001), photonics (Law et al. 2004) chemical sensing, and imaging (Katz and Willner 2004). Recently, there has been a growing interest in Plasmonics nano-particles which have strong effects on the light in visible and invisible regions of the photonics spectrum for applications such as Raman scattering (Kneipp et al. 1997), radiative rate enhancement (Biteen et al. 2005), solar cells (Catchpole and Polman 2008), and optical biosensors (Boriskina et al. 2008). Since optical properties of these particles depend on their size and shape, one of the desirable goals is to control shape of metal and semiconductor nano-particles. Shape control has been successfully demonstrated for gold nano-particles using nonionic surfactants and silver under-potential deposition (Hormozi-Nezhad et al. 2013; Kawamura et al. 2013; Le Ru and Etchegoin 2008). In addition to the recent interest in shape control of nano-particles, optical properties of noble metal particles with their intense colors have fascinated scientists since turn of this century. M. Akhlaghi (B ) Young Researchers and Elite Club, Omidieh Branch, Islamic Azad University, Omidieh, Iran e-mail: m.akhlaghi@sutech.ac.ir F. Emami · N. Nozhat Electro Optics Department, Shiraz University of Technology, Shiraz, Iran 123