含纳米金属阵列阳极氧化铝膜的偏振特性

Polarization Properties of Anodic Alumina Film with Implanted Nanohole Metallic Arrays

利用阳极氧化铝的纳米多孔阵列结构特性 ,将金属Cu电镀到氧化铝的孔中 ,得到含有金属纳米阵列的氧化铝膜。实验发现 ,这种氧化铝膜确实象金属线栅偏振器一样表现出偏振特性 ,是一种新型微偏振器件。它在波长大于 5 0 0nm时吸收很小 ,在波长为 1.5 μm时有高达 6 7.1%的透射率和 2 5 .6dB的消光比。该氧化铝膜的偏振特性与阳极氧化和电镀条件有关。随着电流密度的增大 ,金属柱增多 ,光学损失增大 ,透射率降低 ,而偏振度增大。但是当电流密度增加到某一数值时 ,偏振度降低。通过优化制备条件 ,可得到高效率的氧化铝微偏振器。这种微偏振器制作简单 ,体积小 ,在光电通信领域有着非常广泛的应用前景。

Anodic alumina formed by electrochemical oxidation has a fine structure with a nanohole array. Cu is implanted into the pores of anodic alumina by means of electroplating. With such metallic array, the alumina film exhibits polarization properties like a wire grid polarizer. At the wavelength of 1.5 μm, the film embedded manifests higher transmissivity and better extinction ratio. The dependence of the polarization properties on anodization and electroplating conditions is also studied. To a certain extent, the extinction is enhancing with the increase of anodic oxidation voltage. With the electroplating current density growing, the polarization property is also increasing because of the growth of metallic columns, but the trend is stopped when the current density is too high to make the Joule heat exhale as quickly as possible and result in the irregularity of the columns. The simple microprocessing techniques, the low cost and the small bulk make the film embedded Cu extensive prospects in optical telecommunication.