Abstract
The transmission and effective magnetic properties of a metamaterial consisting of silver nanowires that we call a "silver nanoforest" was investigated using finite element numerical simulations in the optical regime. The variation of these properties with the arrangement and size of the nanowires was also investigated along with resilience to fabrication disorder. The silver nanoforest metamaterial exhibited low loss diamagnetism associated with Fabry Perot interference. In addition to diamagnetism both negative permeability and negative refractive index were obtained, but not simultaneously at same wavelength and geometry. Both negative permeability and negative index experienced significant loss and therefore low transmission due to the plasmonic origins of these effects. Magnetic responses of the silver nanoforest metamaterial were dampened but not inhibited by disorder, with diamagnetic response being the most resilient magnetic response to disorder. A loss reduction method for split ring resonators was investigated. In our finite element simulations this loss reduction occurred somewhat counter-intuitively through the addition of a lossy companion split ring resonator and was indicated by a significant reduction in absorption.