Chen Jianjun, Li Zhi, Lei Ming, Yue Song, Xiao Jinghua, Gong Qihuang
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, China.
Opt Express. 2011 Dec 19;19(27):26463-9. doi: 10.1364/OE.19.026463.
A dielectric-film-coated asymmetric single nanoslit is proposed to realize broadband unidirectional generation of surface plasmon polaritons (SPPs). Due to the tight field confinements by the dielectric film and the deep groove in the asymmetric single slit, the transmittance of the SPPs in the groove to the left side considerably decreases. This greatly suppresses the left-propagating SPP generation efficiency for a broad bandwidth. Meanwhile, the right-propagating SPP generation efficiency has a flat spectra range because of the low transmittance, too. So the unidirectional SPP generation with bandwidth of >100 nm around λ = 750 nm is experimentally achieved for the device lateral dimension of only 865 nm.
提出了一种涂覆介电薄膜的非对称单纳米狭缝，以实现表面等离激元极化激元（SPP）的宽带单向产生。由于介电薄膜和非对称单狭缝中的深槽对场的紧密限制，狭缝中SPP向左侧的透射率显著降低。这在很宽的带宽内极大地抑制了向左传播的SPP产生效率。同时，由于透射率低，向右传播的SPP产生效率也有一个平坦的光谱范围。因此，对于仅865 nm的器件横向尺寸，在λ = 750 nm附近实现了带宽大于100 nm的单向SPP产生。
