Dispersion and extinction of surface plasmons in an array of gold nanoparticle chains: influence of the air/glass interface

We investigate the dispersion relation and extinction properties of surface plasmons in an array of gold nanoparticle chains under spolarized plane wave excitations, through experiment and simulation. Our results reveal that the dispersion and extinction properties of gold nanoparticle chains at an air/glass interface are significantly different from those in a uniform medium. Under total internal reflection, the dispersion is much larger than that above total internal reflection and 100% extinction can be reached. We show that the large dispersion under total internal reflection can be explained by dipole fields and coupling at the air/glass interface. (C) 2008 Optical Society of America.