采用微加工工艺在Si衬底上制备了微柱和微锥阵列, 结合光学建模分析, 研究了结构参数对中长波(2.5~9 μm)红外光反射率的影响规律。使用严格耦合波分析方法(RCWA)计算的微结构反射光衍射效率与傅里叶红外变换光谱仪(FTIR)测试的反射率结果吻合较好。研究结果表明, Si基微结构对TM及TE偏振光均有良好的红外光减反特性, 微锥结构具有更好的减反效果, 2.5~6.5 μm中红外偏振光的反射率低至2%, 同时表现出良好的宽谱与广角度减反特性。

Si based micro-pillar arrays and micro-cone arrays were fabricated using micro processing technology, the reflection performance of the micro structures was studied in the long wave infrared wavelengths (2.5-9 μm) reflection performance of different polarized light. Micro-fabrication combined with modeling analysis of silicon based micro-pillar and micro-cone arrays have been performed to study the effects of structural parameters on the reflectivity of infrared light from 2.5-9 μm. Simulation results using rigorous coupled wave analysis (RCWA) method is in line with the test results from a Fourier transform infrared spectrometer (FTIR). It is found that the antireflection characteristics can be obtained for both transverse electric(TE) and transverse magnetic(TM) polarizations, and the micro-cone arrays have lower reflectivity than the micro-pillar arrays. Moreover, the optimized micro-cone arrays show a reflectivity of only 2% or lower from 2.5-6.5 μm under TM polarization, with wide-spectrum and omnidirectional antireflection characteristics.