长程表面等离子激元的噪声特性及仿真研究

Simulation of amplified noise characteristics in long-range surface plasmon polariton

为了对LRSPPs自发辐射的低噪声放大特性进行深入研究,采用建立长程表面等离子激元(LRSPPs)波导结构和自辐射低噪声放大理论模型的方法,对结构的电磁场分布特性进行了计算仿真,使得设计结构符合LRSPPs传播特性。放大噪声的仿真结果表明:短程表面等离子激元(SRSPPs)大部分自发辐射倏逝到金属区;每单元带宽的有效输入噪声功率达到了7.47×10-4f W/Hz,为常见的相位不敏感放大信号的理论值3倍,表现为THz信号;IR140激发分子的衰变是无辐射的过程,100 nm处自辐射衰减率为SRSPPs和LRSPPs的拐点,之后的辐射过程主要是受自发辐射LRSPPs影响决定。上述研究成果不仅可以明确LRSPPs特性,同时对于其他支持等离子模式的结构也有明显的参考价值。

Long-range surface plasmon polaritons（LRSPPs） which express characteristics of long distances and low-loss are very hot in the plasmonic devices field.In order to conduct deeply research on low noise amplification of spontaneous emission in the LRSPPs,a waveguide structure and its theoretical model of radiation low-noise amplifier were set up.Then this structure was verified through the simulation calculation of the electromagnetic field distribution,which indicated that short-range surface plasmon polaritons（SRSPPs） are evanescent in metal district by spontaneous radiation,the effective noise power of each unit bandwidth reached to 7.47 ×10^-4f W/Hz,three times to common signal amplifier,which expressed THz signal,the decay of IR140 excited molecules is the process without radiation,in which 100 nm at self-radiative decay rate becomes the inflection point for SRSPPs and LRSPPs,and after the inflection point the radiation process is mainly affected by the spontaneous radiation of LRSPPs.These results not only clear the characteristics of LRSPPs,but also have significant reference value for other plasma models.