The Preparation Of Anodic Alumina (Titanium) Photonic Crystals And Their Optical Properties

As a new kind of optical functional materials, photonic crystal has become a research hotspot in the related research field because of its unique optical properties. However, so far the preparation of high-dimensional and shortwave photonic crystal is facing great difficulties. The technology of photonic crystals prepared by anodic oxidation is developed rapidly, but technology parameters have to be further optimized, mechanism of cyclic oxidation needs to be further discussed. Finally, dissertation uses “The preparation of Anodic alumina?Titanium? photonic crystals and their optical properties” as thesis, mostly describes the following works and results:One- dimensional?1D? anodic aluminum oxide?AAO? photonic crystals?PCs? with alternate arrangement of stem channel layer and branched channel layer have been fabricated by using modified periodic pulse anodic technique with simple voltage waveform, and exhibited a narrow photonic band gap?PBG? with extreme low transmittance, steep edge. The center of PBG can be adjusted by the change of voltage parameter. The PBG is very sensitive to the concentration of NaCl solution. Importantly, it is also found that the photoluminescence?PL? intensity is enhanced remarkably when the PC structure was introduced into the AAO, which can be attribute to the introduction of more PL centers into the branched channel layers. The PBG has important effect on the PL intensity.3D TiO₂ photonic crystals?PCs? of multilayers films with the concave morphology of the tube walls were successfully fabricated by using period pulse anodic technique. The pit located in the concave structure cause the change of porosity. The PCs have uniform narrow photonic band gap?PBG?, steep band edge, which were applied successfully in liquid sensors. The centre wavelength of the PBG could be tunable from visible to infrared range by changing the parameters of voltage. The formation mechanism of multilayer is also discussed. The duration of the low voltage is very important for the formation of concave morphology of the tube walls.