基于槽缝结构的太赫兹波超聚焦增强透射结构设计

Super-focusing and enhancement of transmission in the THz region based on a slit-grooves structure design

提出了一种在太赫兹频段可以用来实现超聚焦效应和具有高透射率能力的奇异表面等离子体棱镜结构。这种奇异的棱镜结构是由三个亚波长孔和在金属板两端雕刻有有限个周期性排列的浅槽组成。通过利用表面等离子体激元(SPPs)和超常光学透射(EOT)现象的相关理论,证明了所设计的棱镜结构可以产生一个半高宽(FWHM)约为1/4λ的聚焦点,其透射率是传统的表面等离子体棱镜结构的4.6倍。所设计结构可应用于超分辨成像、光刻、功能性探测等方面。

A novel plasmonic lens was proposed to achieve the super-focusing effects and higher transmission in the THz region.This kind of novel device consists of three sub-wavelength slits engraved into a metal film and surrounded by finite periodic grooves on both sides of the metal slab.Based on the surface plasmon polaritons(SPPs)effects and the extraordinary optical transmission(EOT)effects,we demonstrate that our designed device can generate a focal spot with an full width at half maximum(FWHM)of almost about 1/4 λ and the transmission of plasmonic lens is 4.6 times that of the conventional plasmonic lens.Such kind of plasmonic lens may have potential applications in the super-resolution imaging,lithography,functional detection and so on.