Loss compensated negative index material at optical wavelengths

We present a computational approach, allowing for a self-consistent treatment of three-dimensional (3D) fishnet metamaterial operating at 710 nm wavelength coupled to a gain material incorporated into the nanostructure. We show numerically that loss-free negative index material is achievable by incorporating gain material inside the fishnet structure. The effective gain coefficient of the combined fishnet-gain system is much larger than its bulk counterpart and the figure-of-merit (FOM = | Re(n)/Im(n) |) increases dramatically with gain. Transmission, reflection, and absorption data, as well as the retrieved effective parameters, are presented for the fishnet structure with and without gain.

► We present a computational approach to do a self-consistent full-wave simulation for a fishnet structure operating around 0.7 μm with gain.
► We show that loss-free negative index material is achievable for our simulated fishnet structure.
► The effective gain coefficient of the fishnet-gain system can be much larger than its bulk counterpart.
► The figure of merit can increase dramatically with gain.