title: Ultraviolet true zero-order wave plate made of birefringent porous silica.
abstract: Porous Si made from (110) Si wafers exhibits strong in-plane optical anisotropy (birefringence) in the visible and near-IR ranges. Oxidation of the birefringent porous Si results in the formation of birefringent porous silica. We demonstrate that the degree of the birefringence of porous silica can be controlled by the oxidation condition, and very small birefringence can be achieved. The smallest anisotropy of the refractive index (Δn) is 0.001, which is about ten times smaller than that of quartz. The small birefringence allows us to produce true zero-order wave plates operating in the UV range.
authors.affiliation: Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Shichi
authors.forename: Minoru
authors.initials: M
authors.lastname: Fujii
authors.forename: Shinji
authors.initials: S
authors.lastname: Hayashi