基于亚波长硅波导阵列的透射光场波前调控

发布时间：2018-06-16 19:11

本文选题：信息光学 + 表面光学　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：光学超表面由于亚波长的特征尺寸、自然材料无法实现的传输特性,其概念一经提出,就迅速成为光学集成、平面光学器件研究领域的热门。而基于全电介质材料的光学超表面的提出,由于避免了金属材料的欧姆损耗,将透射型超表面拓展到了可见光和近红外波段。超表面设计的关键,在于结构单元的选择。目前大部分电介质超表面结构单元的设计都是基于米散射理论或几何相位。我们创新性地引入亚波长硅波导作为超表面的结构单元,通过理论计算和数值模拟研究1550 nm波长下对透射光场的波前调控。我们首先研究了基于二维亚波长硅波导阵列的电介质超表面。我们分析了用二维亚波长硅波导做超表面结构单元的可行性,实现了垂直入射线偏振平面波的偏折和近衍射极限会聚,并巧妙地将这二者结合实现了光束的偏折会聚。此外,我们着重考察了二元光学的典型器件——达曼光栅,并在该部分探讨了一维达曼光栅的设计,在远场得到了1×5衍射点阵。之后我们将二维结构拓展到三维,研究了基于三维亚波长硅波导(即矩形波导)阵列的电介质超表面。我们详细讨论了三维亚波长硅波导的光学传输和共振特性,并论证了用三维亚波长硅波导做超表面结构单元的可行性。之后,我们设计了将垂直入射线偏振平面波转换为拓扑荷为1的涡旋光束的超表面,并考察了其与平面波的干涉情况。最后,我们设计了在远场产生5×5等光强衍射点阵的偏振独立达曼光栅,并证明了该达曼光栅具有宽带响应和对制造误差具有鲁棒性的特点。
[Abstract]:Due to the characteristic size of subwavelength, the optical supersurface can not be realized by the transmission characteristics of natural materials. As soon as the concept of optical supersurface is put forward, it has become a hot topic in the field of optical integration and planar optical devices. Because the ohmic loss of metal material is avoided, the transmission supersurface is extended to visible light and near infrared band due to the proposed optical supersurface based on all-dielectric material. The key of supersurface design lies in the selection of structural elements. At present, the design of most dielectric supersurface elements is based on the theory of meter scattering or geometric phase. We creatively introduce subwavelength silicon waveguide as the structural element of supersurface, and study the wavefront control of transmitted light field at 1550 nm by theoretical calculation and numerical simulation. We first study the dielectric supersurface based on the Si-waveguide array. We analyze the feasibility of using the two-dimensional wavelength silicon waveguide as the supersurface structure unit, and realize the deflection and near diffraction limit convergence of the plane wave polarized by perpendicular ray, and skillfully combine the two to realize the beam deflection and convergence. In addition, we focus on the Darman grating, a typical binary optical device, and discuss the design of the one-dimensional Daman grating in this part. The 1 脳 5 diffraction lattice is obtained in the far field. Then we extend the 2D structure to 3D structure and study the dielectric supersurface based on 3D subwavelength silicon waveguide (rectangular waveguide) array. We discuss in detail the optical propagation and resonance characteristics of the SWA waveguides and demonstrate the feasibility of using them as supersurface structural elements. Then we design the supersurface of the vertically-polarized plane wave to a vortex beam with topological charge of 1 and investigate its interference with the plane wave. Finally, we design a polarization-independent Darman grating which produces 5 脳 5 equal-intensity diffraction lattice in the far field, and prove that the Darman grating has the characteristics of wideband response and robustness to manufacturing errors.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN25

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