偏振调控的动态表面等离激元器件的研究

Dynamic surface plasmon polaritons (SPPs) devices is a frontier topic of nano-photonics. The amplitude and phase of SPPs are closely related to the polarization of incident light. Utilizing the polarization to realize dynamic SPPs devices is an effective and convenient method. In this project, based on the interaction between subwavlength structure unit and light with different polarization, the focus, vortex and propagation direction of SPPs generated by semicircular slit, spiral slit and fishbone shaped slit array will be studied with Huygens-Fresnel principle for SPPs. Polarization controlled SPPs Bessel beam device and polarization controlled SPPs Airy beam device will be designed and experimentally studied. The order of the SPPs Bessel beam or the propagation direction of the SPPs Airy beam can be dynamically modulated by changing the polarization of the incident light. The work of this project may have potential applications in polarizaiton based information transmission and process, the detection of the polarization state of light, biological molecule spectroscopy and sensing and the design of new polarization controlled SPPs devices.

动态表面等离激元（SPPs）器件的研究是纳米光子学的前沿课题，SPPs的振幅和相位与激发光偏振密切相关，利用偏振实现动态调控的SPPs器件是一种简单有效的途径。本项目拟以亚波长结构单元与不同偏振光相互作用激发SPPs的规律为基础，结合SPPs的惠更斯菲涅尔原理研究分析三种结构偏振调控SPPs器件（半圆环狭缝、螺旋狭缝和鱼骨形狭缝阵列）产生的SPPs焦点、涡旋和传播方向随入射光偏振改变的演化规律，设计并实验验证偏振调控SPPs Bessel光束器件和偏振调控SPPs Airy光束器件，实现利用偏振调控SPPs Bessel光束的阶数（零阶和一阶）和SPPs Airy光束的传播方向。研究结果将对于偏振控制的信息传递与处理、光波偏振态的检测、手性生物分子光谱与传感和新型偏振控制SPPs器件的设计等有潜在的应用前景。

利用光波偏振动态调控表面等离激元（SPPs）光场是一种简单有效的手段。本项目研究了亚波长结构（单狭缝、双狭缝）与不同圆偏振光相互作用激发SPPs的规律，并基于此实现了SPPs聚焦、艾里光束和贝塞尔光束的动态调控。为了引入额外的螺旋相位，设计了半圆环狭缝阵列SPPs透镜，使左旋和右旋圆偏振光激发的SPPs焦点分离达到1500nm（为此前文献报道结果的6倍），并建立了焦点偏移距离与螺旋相位的关系；设计了超表面器件在近场（SPPs）和透射场同时产生艾里光束，实现了通过控制圆偏振光的手性改变SPPs艾里光束的位置，而且分析了艾里光束的自弯曲、无衍射和自愈特性；设计了旋转三棱镜形狭缝阵列结构产生SPPs贝塞尔光束，水平和竖直线偏振光分别产生零阶和一阶SPPs贝塞尔光束，圆偏振光会导致SPPs贝塞尔光束的位置向上或向下偏移。上述研究成果在基于偏振的片上通信和粒子操控等方面具有潜在的应用前景。