Zeng Jinwei, Luk Ting S, Gao Jie, Yang Xiaodong
Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO, 65409, USA.
Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA.
Sci Rep. 2017 Sep 19;7(1):11824. doi: 10.1038/s41598-017-12143-7.
Miniaturized quarter-wave plate devices empower spin to orbital angular momentum conversion and vector polarization formation, which serve as bridges connecting conventional optical beam and structured light. Enabling the manipulability of additional dimensions as the complex polarization and phase of light, quarter-wave plate devices are essential for exploring a plethora of applications based on orbital angular momentum or vector polarization, such as optical sensing, holography, and communication. Here we propose and demonstrate the magnetic metamaterial quarter-wave turbines at visible wavelength to produce radially and azimuthally polarized vector vortices from circularly polarized incident beam. The magnetic metamaterials function excellently as quarter-wave plates at single wavelength and maintain the quarter-wave phase retardation in broadband, while the turbine blades consist of multiple polar sections, each of which contains homogeneously oriented magnetic metamaterial gratings near azimuthal or radial directions to effectively convert circular polarization to linear polarization and induce phase shift under Pancharatnum-Berry's phase principle. The perspective concept of multiple polar sections of magnetic metamaterials can extend to other analogous designs in the strongly coupled nanostructures to accomplish many types of light phase-polarization manipulation and structured light conversion in the desired manner.
小型化四分之一波片装置实现了自旋到轨道角动量的转换以及矢量偏振的形成，它们是连接传统光束和结构化光的桥梁。四分之一波片装置能够操控光的复偏振和相位等额外维度，对于探索基于轨道角动量或矢量偏振的众多应用至关重要，如光学传感、全息术和通信。在此，我们提出并展示了可见光波长下的磁性超材料四分之一波片涡轮，以从圆偏振入射光束产生径向和方位角偏振的矢量涡旋。磁性超材料在单波长下作为四分之一波片表现出色，并在宽带内保持四分之一波的相位延迟，而涡轮叶片由多个偏振部分组成，每个部分包含在方位角或径向附近均匀取向的磁性超材料光栅，以根据潘查拉特纳姆 - 贝里相位原理有效地将圆偏振转换为线偏振并诱导相位偏移。磁性超材料多偏振部分的这一前瞻性概念可以扩展到强耦合纳米结构中的其他类似设计，以期望的方式完成多种类型的光相位 - 偏振操纵和结构化光转换。
