金属导线偶合THz表面等离子体波

Terahertz surface plasmon polariton couping on brass rods

利用THz时域光谱技术,研究了具有不同排列参数的金属导线阵列的透射特性,分析了金属导线半径,排列间隔以及入射电场的偏振方向对表面等离子体波产生和传播的影响.在具有等间隔缝隙的金属导线中,当电场偏振方向垂直金属导线时,透射信号受等离子模式和谐振腔模式的共振效应的影响;而当电场偏振平行金属导线时,只存在谐振腔模式的共振.

In the experiment for studying the nature of coupling between suface plasmon （SP） wave and terahertz radiation by subwavelenth-sized brass rods, we found that the polarization of the THz field, size of rods, and slit between rods critically affect the coupling efficiency. By the method of Fourier transform of the time domain data, we found the coupling frequency in THz range. With equal slits between the brass rods, we demonstrated thar the transmission resonance is attributed to the combined effects of surface plasmon and cavity mode resonance when the electric vector is perpendicular to the grating wires, while the cavity mode resonance dominates the resonance transmission when they are parallel.