闪耀型IR/MMW复合器红外衍射效率的几点改进

为了将不同方向的红外与毫米波复合成同一出射方向,现在国内多采用频率选择表面原理与红外高反原理。前者十分复杂,制造非常困难并且误差很大;后者的镀膜平面板会改变微波偏振状态,而且装配时还要求倾斜,这给安装也带来问题。两者在做大尺寸元件时,其成本会变得非常昂贵。而基于闪耀光栅原理能够很好地解决这些问题,当选用对毫米波全透的材料时,主要解决的就是提高红外衍射效率。针对实际制作工艺不可避免的表面粗糙度与零级面,给出了理论公式。并采用变周期的方法提高红外衍射效率。

Improvements to infrared diffractive efficiency of IR/MMW grating wave beam combiner

At present,the principle of frequency selective surface and the principle of IR coating are adopted to combine different orientations of IR and MMW to uniform direction.The former is very complicated,difficult to fabricate and has large error.The later has some drawbacks of the incidence polarization changing and difficult fixing.When manufacture large size combiner,both become very expensive.Using the blaze grating can solve those problems.The main purpose is improve IR diffraction efficiency when utilize the material of pass-through MMW.The formulas of diffraction efficiency about zero-order surface and roughness have been given which are inevitable in fabrication.And chirp gratings are adopted to improve the diffraction efficiency.