Interfaces Make all the Difference in Metamaterial Advancement
Researchers now understand why artificially engineered materials, known as metamaterials, can sometimes perform better than expected. Metamaterials are built from small, engineered structures that manipulate light in ways not found in nature. Unfortunately, energy is typically lost by the conversion of light to heat in the metallic components and typical support materials; this is a key challenge for application development. When a metamaterial is coupled with a support that has a so-called gain material at its surface, the results are unexpected —transmission losses are significantly reduced compared to the support or metamaterial alone. A new approach for simulating the coupling of the metamaterial to the support helps explain why. When these coupled systems are hit with a laser pulse, light absorption and reflection are both affected, albeit differently. If this effect is applied properly the efficiency of the device is improved. For many of the proposed applications of metamaterials, such as perfect lenses, low-loss or even zero-loss materials are required. This new understanding will help scientists explore material designs that will best reduce losses.
- Zhixiang Huang, Th. Koschny, and C. M. Soukoulis, Theory of Pump-Probe Experiments of Metallic Metamaterials Coupled to a Gain Medium. Physical Review Letters, 2012, 108, 187402. DOI: 10.1103/PhysRevLett.108.187402