宽带近红外表面等离激元逻辑与门器件的设计

Design of broadband near infrared surface plasmonic polaritons logic AND gates device

提出了一种宽带近红外表面等离激元逻辑与门纳米结构。两个输入端由相互平行的狭缝天线构成的近红外宽带定向表面等离激元耦合器构成。这种放置在圆弧上的耦合器阵列纳米结构在径向偏振光照射下表面等离激元具有聚焦特性。两个相同的这种圆弧形纳米结构产生的表面等离激元聚焦光斑分别由两个槽型波导传输到输出端叠加干涉。在发生线性干涉时,两个振幅相同,偏振方向一致,相位差为零的表面等离激元干涉强度为单个圆弧形纳米结构产生的表面等离激元强度的4倍。理论分析了结构和器件原理,并用时域有限差分法软件模拟了输入输出逻辑关系以及宽带特性。

A nanostructure of broadband surface plasmons logic AND gate was presented. The two input ports were composed of broadband infrared directional couplers which were a pair of two parallel slot nano-antennas milled into gold film. An array of couplers arranged on an arc-shaped circle was capable of focusing the surface plasmons to the circular center when it was illuminated with radially polarized beam. The same two focused surface plasmons spots were coupled into two groove-shaped waveguides,respectively, and then interfered each other at the cross point. The intensity was four times that of intensity produced by a single arc-shaped nanostructure when two arc-shaped nanostructures produced the surface plasmons in the center with the same amplitude, polarization direction and zero phase difference.The nanostructure and device principle were theoretically analyzed. The relation between input ports and output port along with broadband property were simulated with the finite difference in time domain method.