Tian Yi, Sun Gang, Li Fan, Yan Hui, Zhang Li, Li Zhuo
Appl Opt. 2014 Jun 20;53(18):3875-83. doi: 10.1364/AO.53.003875.
The design method of an infrared/millimeter wave mirror array type of beam combiner was investigated. The beam combiner was composed of a support plate, air gap, and mirror array. It had two advantages: one was that the size of the beam combiner could be extended by splicing more mirrors; the other was that the millimeter wave passband could be tuned by adjusting the thickness of the air gap. The millimeter wave and infrared structure was designed by using transmission line theory and optimized by a simplex Nelder-Mead method. In order to analyze the influence of deformation on performance, the mechanical characteristics of the mirrors and support plate were analyzed by the finite element method. The relationship between the millimeter wave transmission characteristics and the air gap was also analyzed by transmission line theory. The scattered field caused by pillars was computed by the multilevel fast multipole method. In addition, the effect of edge diffraction on the near field uniformity was analyzed by the aperture field integration method. In order to validate the mirror array splicing principle and the infrared imaging performance, a prototype of the mirror array was fabricated and tested. Finally, the infrared images reflected by the mirror array were obtained and analyzed. The simulation and experiment results validated the feasibility of the mirror array beam combiner.
研究了一种红外/毫米波镜阵列型光束组合器的设计方法。该光束组合器由支撑板、气隙和镜阵列组成。它有两个优点：一是通过拼接更多的镜子可以扩展光束组合器的尺寸；二是通过调整气隙厚度可以调谐毫米波通带。利用传输线理论设计毫米波和红外结构，并采用单纯形Nelder-Mead方法进行优化。为了分析变形对性能的影响，采用有限元方法分析了镜子和支撑板的力学特性。还通过传输线理论分析了毫米波传输特性与气隙之间的关系。采用多级快速多极子方法计算柱体引起的散射场。此外，采用孔径场积分方法分析了边缘衍射对近场均匀性的影响。为了验证镜阵列拼接原理和红外成像性能，制作并测试了镜阵列原型。最后，获取并分析了镜阵列反射的红外图像。仿真和实验结果验证了镜阵列光束组合器的可行性。
