title: Subtle vertical structures of porous anodic alumina films for use as waveguides.
abstract: Since porous anodic alumina (PAA) is a frequently-used optical waveguide material, accurate characterization of its structure parameters and optical properties is in urgent need. To characterize PAA, spectroscopic ellipsometry is preferred due to its undamaged detection, no sample pretreatment, and having a coverage area relatively larger than that of scanning electron microscopy. For spectroscopic ellipsometric data fitting, previous studies usually adopted a four-layer model, which displays a large bias from the raw data. Here, a modified six-layer model is built in consideration of the more elaborate porous layer that is the dominating contributor for the optical property of a PAA film. By using this six-layer model, PAA films with different thicknesses and under different oxidation voltages were analyzed, and the disperse curves of the porous layer were provided. This study will be helpful for learning the subtle structure of PAA and widen its applications for optical purposes.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Wu
authors.forename: Shuping
authors.initials: S
authors.lastname: Xu
authors.forename: Haining
authors.initials: H
authors.lastname: Cui
authors.forename: Weiqing
authors.initials: W
authors.lastname: Xu