Metamaterials And Its' Numerical Calculations

Metamaterial has attracted people's attention because of its unique characteristics in electromagnetic field. There is no natural matter with such distinctive feature. Many years ago, a scientist brought up such concept as "Negative refraction", but not until 2000, Dr Smith and his group in the University of California, San Diego managed to fabricate a metamaterial sample with negative refractive index, the first one in the world ever, and proved the existence of negative refraction and negative refractive index, publishing the first paper about metamaterial in Science. After then, every year lots of research in this field has been done and results published.Three methods are usually employed when fabricating metamaterial, the photonic crystal method, the metallic metamaterial method and the self-assembly method. Compared to the photonic crystal method, metallic method realized at near-IR or visible frequency is more difficult experimentally due to strict requirement of fabrication and to the generally poor optical properties of metals at these wavelengths. The self-assembly method is often used with colloid particles to self-organize into specific structures (fractals) to realize negative refraction.COMSOLBased on finite element method, this work gets the computational simulation results of a special structure—metal-dielectric-metal structure using multi-physics coupled software COMSOL. It confirms the property of negative indices of-both metamaterials in the theoretical level, and provides some ideas for further studies of new, more experimental realizable and stable artificial structures. Second, we use the same software to confirm another self-assembled structure having the same negative refraction phenomenon.