Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica, Universidad Miguel Hernández de Elche, 03202, Elche, Spain.
Department of Physics, San Diego State University, California, 92182-1233, USA.
Sci Rep. 2017 May 22;7(1):2216. doi: 10.1038/s41598-017-02328-5.
We present a proof of concept for a vector beam polarization state spectrum analyzer based on the combination of a polarization diffraction grating (PDG) and an encoded harmonic q-plate grating (QPG). As a result, a two-dimensional polarization diffraction grating is formed that generates six different q-plate channels with topological charges from -3 to +3 in the horizontal direction, and each is split in the vertical direction into the six polarization channels at the cardinal points of the corresponding higher-order Poincaré sphere. Consequently, 36 different channels are generated in parallel. This special polarization diffractive element is experimentally demonstrated using a single phase-only spatial light modulator in a reflective optical architecture. Finally, we show that this system can be used as a vector beam polarization state spectrum analyzer, where both the topological charge and the state of polarization of an input vector beam can be simultaneously determined in a single experiment. We expect that these results would be useful for applications in optical communications.
我们提出了一种基于偏振衍射光栅 (PDG) 和编码谐波 q 板光栅 (QPG) 组合的矢量光束偏振态光谱分析仪的原理验证。结果，形成了一个二维偏振衍射光栅，在水平方向上产生了六个不同的 q 板通道，拓扑电荷从-3 到+3，每个通道在垂直方向上在相应的更高阶庞加莱球的顶点处分裂为六个偏振通道。因此，并行生成 36 个不同的通道。使用反射光学架构中的单个纯相位空间光调制器对这种特殊的偏振衍射元件进行了实验验证。最后，我们表明，该系统可用作矢量光束偏振态光谱分析仪，其中输入矢量光束的拓扑电荷和偏振状态都可以在单次实验中同时确定。我们预计这些结果将对光通信应用有用。
