Chen Yuyan, Wang Yongkai, Wang Tiankun, Zhang Yongyuan, Wang Li, Zhang Zhongyue
Appl Opt. 2017 Jul 10;56(20):5781-5785. doi: 10.1364/AO.56.005781.
Asymmetric transmission (AT) has significant applications in optical polarization control. In this paper, we propose a kind of periodic nanoslit rather than the protruding planar structures, such as G-shaped structure and coupled split-ring resonators, to realize the AT effect. The planar periodic obliquely intersecting nanoslits (OINs) in the gold film, composed of gratings with an infinite length and tilted nanoslits with a finite length, are proposed to realize the AT effect by performing the finite element method. Obvious dips in the AT spectra result from the circular localized surface plasmon resonance around the two terminals of the tilted nanoslits and from the surface plasmon polariton resonances on the film and in the gratings or tilted nanoslits. In addition, the AT effect strongly depends on the geometric parameters of the OINs. The film can be straightly powered on as an in-plane electrical conductor, which broadens its applications in optoelectronic devices. Overall, these results are beneficial in designing devices to achieve AT for polarization transformation.
非对称传输（AT）在光偏振控制中具有重要应用。在本文中，我们提出了一种周期性纳米狭缝，而非诸如G形结构和耦合开口环谐振器等突出的平面结构，以实现AT效应。通过有限元方法，我们提出了金膜中的平面周期性斜交纳米狭缝（OINs），其由无限长的光栅和有限长的倾斜纳米狭缝组成，以实现AT效应。AT光谱中明显的凹陷源于倾斜纳米狭缝两端周围的圆形局域表面等离子体共振以及薄膜、光栅或倾斜纳米狭缝中的表面等离子体激元共振。此外，AT效应强烈依赖于OINs的几何参数。该薄膜可作为面内电导体直接通电，这拓宽了其在光电器件中的应用。总体而言，这些结果有助于设计实现用于偏振转换的AT的器件。
