Department of Physics, Imperial College London, London, United Kingdom.
Phys Rev Lett. 2011 Oct 14;107(16):167405. doi: 10.1103/PhysRevLett.107.167405. Epub 2011 Oct 13.
We establish a theory that traces light amplification in an active double-fishnet metamaterial back to its microscopic origins. Based on ab initio calculations of the light and plasmon fields we extract energy rates and conversion efficiencies associated with gain and loss channels directly from Poynting's theorem. We find that for the negative refractive index mode both radiative loss and gain outweigh resistive loss by more than a factor of 2, opening a broad window of steady-state amplification (free of instabilities) accessible even when a gain reduction close to the metal is taken into account.
我们建立了一个理论，该理论追溯了活性双渔网超材料中光放大的微观起源。基于对光和等离子体场的从头计算，我们直接从坡印廷定理中提取出与增益和损耗通道相关的能量速率和转换效率。我们发现，对于负折射率模式，辐射损耗和增益都超过电阻损耗 2 倍以上，即使考虑到接近金属的增益降低，也能打开一个稳定放大（无不稳定性）的宽窗口。
