Design of broadband metal nanosphere antenna arrays with a hybrid evolutionary algorithm

This paper presents a method for the design of metal nano-sphere antenna arrays with broadband plasmonic eld enhancement over the whole visible spectra. In particular thanks to a customized hybrid genetic algorithm (HGA), the plasmonic near eld enhancement and the side-lobes level are maximized and minimized respectively by thinning the nano-array, optimizing the elements spacing and dimensions. In particular the problem is recast as an optimization one by dening a suitable cost function which is then minimized with the HGA. The obtained preliminary results demonstrate the potentialities of the proposed approach.