Influence of metal-layer thickness on the losses in fishnet metamaterial

The influence of metal-layer thickness on the left-handed performance of fishnet metamaterial is investigated. It is found that an appropriate thickness design of the metal layer is important for reducing losses and increasing the figure of merit. Low-loss and extraordinary transmission can be achieved for the fishnet metamaterial operating around 1.5 mum with the metal-layer thickness of about 90 nm, which is larger than the conventionally reported thickness of about two times of the skin depth.