In-plane anisotropy of ZnTe nanoparticle-doped glass thin films fabricated by simultaneous oblique deposition from two opposing directions

Abstract

ZnTe nanoparticle-doped glass thin films which have quite unique anisotropies in microscopic structures and in optical properties in the thin film plane were fabricated by introducing ZnTe into nanometer-scaled voids included in well-known columnar structures of obliquely deposited SiO2 films. ZnTe and SiO2 were simultaneously deposited on substrates from two opposing oblique directions and then the samples were annealed. The samples consisted of two kinds of portions with planar shape; the portions of amorphous ZnTe (as-deposited samples) or condensing ZnTe nanocrystallites (postannealed samples) were stacked alternatively with SiO2 portions in the thin film plane in the direction parallel to the plane including the two deposition directions. In-plane anisotropies in the refractive indices, the absorption coefficients, and the third-order nonlinear optical susceptibilities were evaluated. The anisotropies in the optical properties were revealed to be due to the fact that the distribution of the electric field of the incident light in the composite (inhomogeneous) samples depends on the polarization because of the structural anisotropy.