提出了具有增透抗反特性的同轴环状孔阵列纳米结构,利用时域有限差分法(FDTD算法)分析了其光学特性并给出优化的结构.FDTD模拟结果表明,仅由SiO2单层材料构成的纳米结构,其透过率受材料的吸收特性影响极小,主要受表面面形、环状孔内外半径、深度和周期等结构参量影响.在环状孔阵列结构上采用占空比逐渐增大的设计,能有效增加可见光谱区(400～700 nm)的增透抗反特性.并给出了优化后的设计参数:最小内径50 nm,最大外径150 nm,深度200nm,周期300 nm,其在可见光谱区的平均透射率大于99.5％,且光波在表面法线的±20°范围内入射时,反射率小于0.6％.%A antireflective structure based on subwavelength coaxial annular hole arrays combining the function of high transmittance and antireflection is proposed, and its optical properties is analysised and the best optimization structure is given by FDTD. FDTD simulation results show that transmittance of the single layer nanostructures made of SiO2 only, which is littel related with material absorption characteriatica, is mainly affected by structural parameters such as the surface shape, the duty cycle, the depth and period of the circular hole. The design,which the duty cycle gradually increase in cir-cular hole array, can effectively increase antireflective features in the visible spectral region(400～ 700 nm). The optimized design parameters are given: the minmum inner diameter R1 ( min) = 50 nm, the maximum outer diameter R2 (max) = 150 nm, depth H = 200 nm, period T = 300 nm, and its average transmittance is greater than 99. 5% in the visible spectral region. The reflection rate is smaller than 0. 6% in the case of light waves within ±20° range of the surface normal incidence.
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