为了研究纳米金属银薄膜和空气构成的周期结构的光学传输特性, 采用周期结构的Bloch原理和传输矩阵法研究了光波在其中的传输特性。由分析可知, 对特定的入射角度, 有多个分离的频道可以让光波传播; 对特定的光波频率, 有多个入射方向让光透射。通过改变空气层的厚度, 频道位置和角谱位置可以根据需要进行调节。银层在研究的光谱范围内的损耗对传输的透射率产生影响, 但不改变滤波通道的位置。通过设计合适的厚度, 这种影响可以得到有效的降低。结果表明, 可以将该结构设计成多通道频率滤波器和多通道角度滤波器。

The optical transmission property of Ag-air nanofilm was studied based on Bloch’s theorem and the transfer matrix method. At a given incident angle, there are some discrete frequency channels; at a given frequency, there are also some discrete spatial channels. Through changing the thickness of air, the positions of frequency channels and spatial channels can be easily adjusted. The loss of Ag influences the transmittance but does not change the position of filtering channel. Through decreasing the thickness of Ag layer, the loss cannot influence the filtering function of the Ag-air structure. The results indicate that the Ag-air structure can be used as a multi-channel frequency filter and spatial filter.