Anomalous absorption by multi-layered media

Recent studies have shown that an anomalously strong absorption occurs if a plane wave is incident on specialized layered configurations that exhibit slight losses. By studying the reflectance properties of multi-layered media, we show that such effects may occur in all structures that support leaky waves. This result implies that total or nearly total absorption of energy is possible in a much broader class of layered configurations than was recognized hitherto.