在同一聚碳酸酯基底上制作了6个不同方向的双层金属光栅偏振器, 用于消除分立器件带来的安装误差。将该偏振器应用于偏振导航传感器上并进行了测角精度测试, 基于神经网络法研究了角度测量的误差补偿方法。首先, 基于严格耦合波理论设计了一种亚波长双层金属光栅偏振器, 分析了它的周期和金属厚度对偏振器性能的影响, 其在510 nm波长入射时TM偏振光透射率高于71%, 消光比大于2 100。应用纳米压印技术在聚碳酸酯基底上加工制作了设计的偏振器, 其基底上设有6块结构参数相同但朝向不同的双层金属光栅结构。将此偏振器安装在偏振导航传感器上并在测试平台上测试了测角精度, 测试的原始误差在±1°以内; 经BP神经网络法误差补偿后, 测角误差在±0.2°以内。得到的结果可较好地满足偏振导航的要求。

Multi-orientated bi-layered nano wire polarizers were fabricated in a polycarbonate (PC)substrate to eliminate the alignment error caused by the discrete components. The polarizers were used in a polarization navigation sensor, the angular error was tested and the angular error compensation algorithm based on neural network was analyzed. First, the bi-layered nano wire polarizers were designed using Rigorous Coupled Wave Analysis (RCWA) and the effects of grating period and metal layer thickness on the polarizer performance were analyzed in detail. Experiments show that the polarizer has TM transmittance of 71% and extinction ratio of 2 100 for the wavelength of 518 nm. The polarizer was fabricated based on nanoimprint lithography and six polarizers were mounted in the substrate with the same structure but different orientations. After that, the polarizer was applied to a polarization navigation sensor and the angular error was measured at a measurement platform. Results indicates that the original angular error is within ±1° , but it is ±0.2° when is compensated by using Back Propagation(BP) neural network compensation algorithm. The proposed polarizer could fulfill the needs of polarization navigation systems.