Analysis and comparison of simulation techniques for silver superlenses

Transfer-matrix and finite element modelling techniques were used to simulate single- and multi-layer silver-based superlenses. The techniques were compared for their abilities to simulate sub- diffraction-limited resolution and DC transmission. The finite element modelling technique confirmed conclusions drawn from T-matrix analysis, namely that multi-layer superlenses had greater transmission over a larger window of spatial frequencies than single-layer superlenses and that superlens performance was adversely affected by resonances at different frequencies. The failure of the T-matrix technique to model interactions between the mask and lens was identified as one of the main sources of inaccuracy; however, the technique remained valuable due to its superior computational efficiency compared to finite element modelling.