Department of Electrical & Computer Engineering, Boston University, Boston, Massachusetts 02215, USA.
Opt Lett. 2012 Dec 15;37(24):5076-8. doi: 10.1364/OL.37.005076.
In this Letter, we experimentally demonstrate structured light carrying multiple values of orbital angular momentum (OAM) in the farfield scattering region of Vogel spiral arrays of metallic nanoparticles. Using Fourier-Hankel mode decomposition analysis and interferometric reconstruction of the complex amplitude of scattered waves, we show the ability to encode well-defined numerical sequences, determined by the aperiodic spiral geometry, into azimuthal OAM values, in excellent agreement with analytical scattering theory. The generation of azimuthal sequences of OAM values by light scattering from engineered aperiodic surfaces is relevant to a number of device applications for secure optical communication, classical cryptography, and quantum cryptography.
在这封信件中，我们实验证明了在金属纳米粒子的 Vogel 螺旋阵列的远场散射区域中，结构光携带多个轨道角动量（OAM）的值。通过傅里叶-汉克尔模式分解分析和散射波复振幅的干涉重构，我们展示了将由非周期性螺旋几何形状确定的明确定义的数值序列编码为角向 OAM 值的能力，与分析散射理论非常吻合。通过从工程非周期性表面散射的光产生 OAM 值的角向序列与许多设备应用相关，例如安全光通信、经典密码学和量子密码学。
