We discuss the possibility of using a direct electric current pump in order to amplify a mid-infrared surface plasmon polariton (SPP) in a single-walled carbon nanotube (CNT) deposited on a substrate. Amplification is achieved providing that the phase velocity of the SPP and the drift velocity of the charge carriers in the nanotube are matched. Calculating the amplification characteristics involves numerical simulations that allow to account for the influence of the substrate on the dispersion and inhomogeneity of the plasmon mode field distribution across the CNT. The spectral behaviour of an amplified SPP is shown to exhibit a high sensitivity to variations of the refractive index of the substrate supporting the CNT. We propose a design for the resonant amplification of SPPs with a DC current pump, in which a distributed resonator is obtained with a periodical modulation of the refractive index of the substrate.

我们讨论了使用直流电泵来放大沉积在基板上的单壁碳纳米管（CNT）中的中红外表面等离子体激元（SPP）的可能性。只要SPP的相速度和纳米管中电荷载流子的漂移速度匹配，就可以实现放大。计算放大特性涉及数值模拟，该数值模拟可考虑基材对跨CNT的等离激元模场分布的分散性和不均匀性的影响。放大后的SPP的光谱行为显示出对支撑CNT的基材的折射率变化具有高度的敏感性。我们提出了一种使用直流电流泵对SPP进行谐振放大的设计，