| Summary: | 博士 === 國立中央大學 === 光電科學研究所 === 95 === There are two important topics on optical coatings. First, we have to develop thin film materials with good optical properties, mechanical properties, and environmental stability. Second, we need to develop new methods to design optical multilayer coatings. The development of the new materials is helpful to study these two topics. Mixing two thin film materials is an interesting technology to develop new thin film materials.
In this article, the radio frequency ion-beam sputtering deposition (RF-IBSD) system was used to prepare composite films. An ion source was used to bombard two targets simultaneously. The composite proportions are determined by the area ratio of two targets and the area ratio could be adjusted by moving the targets with a step motor. In this experimental have two parts. First, to study the material of high refractive index composite film, Ta2O5-TiO2 composite films prepared by Ti and Ta targets. The refractive indices and extinction coefficients of the composite films were found to be between those of the TiO2 and Ta2O5 films. The structure of the as-deposited films was amorphous, and the surface roughness was about 0.1 nm. The residual stress of the composite films was less than that of pure TiO2 film. The structure of the composite films after annealing was amorphous, with low surface roughness and slightly increased residual stress. Second, to study the gradient-index composite films, Ta2O5-SiO2 composite films were prepared by Ta and SiO2 targets. Ta2O5-SiO2 composite films with refractive indices varied from 1.52 to 2.16, and low extinction coefficient was about 10-4@550nm. All the composite films were amorphous and had surface roughness less than 0.1 nm. The residual stress and substrate deflection of rugate filter would be smaller than that of the multilayer filter which was made by stacking up alternatively with high and low refractive index materials. To sum up, the composite films could be used for high quality optical coating materials and gradient-index optical coating.
|
|---|
