中国物理B ›› 2010, Vol. 19 ›› Issue (7): 77803-077803.doi: 10.1088/1674-1056/19/7/077803
徐海清1, 付少丽1, 谢素霞2, 李宏建2, 周昕2
Xie Su-Xia(谢素霞)a)b), Li Hong-Jian(李宏建)a)b)†, Zhou Xin(周昕)a)b), Xu Hai-Qing(徐海清)a), and Fu Shao-Li(付少丽)a)
摘要: We investigate the relationship between the transmission and the layer distance of double-layer gold slit arrays by using the finite-difference time-domain method. The results show that the transmission properties can be influenced strongly by layer distance. We attribute the two types of resonant modes to surface plasmon resonance and the localised waveguide resonance. We find that the localised waveguide transmission peak redshifts and becomes broader with increasing layer distance D. We also describe and explain the splitting, shift, and degeneration of the surface plasmon resonant transmission peak theoretically. In addition, to clarify the physical mechanism of the transmission behaviours, we analyse the distributions of electric field and total energy for the three transmission peaks with distance D=45 nm for the double-layer system. Light transporting behaviours are mostly concentrated in the region of the slits as well as the interspaces of the two layers, and for different resonant wavelengths the electric field and energy distributions are different. It is expected that the results obtained here will be helpful for designing subwavelength metallic grating devices.
中图分类号: (Collective excitations (including excitons, polarons, plasmons and other charge-density excitations))