Transmission of silica sub-wavelength nano-microstructure

The paper studies the optical performance of a new sub-wavelength nanostructure which consists of non-close-packed polycrystalline colloidal crystals fabricated by dip-coating. Effective medium theory (EMT) is used to analyze the optical property of the as prepared structure. The structure exhibits excellent transmission performance. It can turn the maximum transmission wavelength from visible light to infrared wave by different withdrawal speed. The structure can be used for antireflection coating, and the measured effective refractive index is 1.22, and the maximum transmission of a glass substrate is increased to 99.8%.