Ellipsometric Characterization of Thin Films from Multicomponent Chalcogenide Glasses for Application in Modern Optical Devices

Abstract

A review is given on the application of the reflectance ellipsometry for optical characterization of bulk materials and thin films with thickness betweenλ/20 and 2λ(atλ=632.8 nm). The knowledge of the optical constants (refractive index,n, and extinction coefficient,k) of thin films is of a great importance from the point of view of modelling and controlling the manufacture of various optical elements, such as waveguides, diffraction gratings, and microlenses. The presented results concern the optical properties of thin films from multicomponent chalcogenide glasses on the base of As2S3and GeS2determined by multiple-angle-of-incidence ellipsometry and regarded as a function of the composition and thickness. The homogeneity of the films is verified by applying single-angle calculations at different angles. Due to decomposition of the bulk glass during thermal evaporation, an optical inhomogeneity of the thin As (Ge)-S-Bi(Tl) films is observed. The profile ofnin depth of thin As-S-Tl (Bi) films was investigated by evaporation of discrete layers. It is demonstrated that homogenous layers from the previous compounds with controlled composition can be deposited by coevaporation of As2S3and metals or their compounds (Bi, Tl, In2S3).

Optical properties and surface structuring of Ge20Sb5S75 amorphous chalcogenide thin films deposited by spin-coating and vacuum thermal evaporation

“…Measured composition of as-prepared TE thin film was Ge21.0Sb6.5S72.5, which slightly differs from planned Ge20Sb5S75 composition. The difference between the planned glass composition and as-prepared TE thin film can be attributed to the non-ideality of evaporation process when partial fractionation can be expected [24][25]. The EDS data proved that Ge21.0Sb6.5S72.5 TE thin film composition was not changed after annealing or UV exposure.…”

Superiority of Graphene over Polymer Coatings for Prevention of Microbially Induced Corrosion

“…Woollam Co., Inc, NE, USA). The observed reflected light was used to determine ratios of the amplitude (ψ) and phase changes of the p and s components of polarized light (Δ) 57 58 . A WVASE 32® model was used to minimize mean square error (MSE) and fit the experimental data.…”

Optical Characterization of Inhomogeneous Thin Films Deposited onto Non-Absorbing Substrates

“…While significant attention has been dedicated to developing suitable methods for the optical characterization of homogeneous thin films, as evidenced by the abundance of publications on the subject represented here by a small selection [1][2][3][4][5][6][7][8][9], much less attention has been paid to the optical characterization of inhomogeneous thin films with refractive index profiles along the axis perpendicular to the film boundaries. Nevertheless, several papers have addressed this issue [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The optical characterization of inhomogeneous thin films is more complicated than that of homogeneous thin films, mainly due to a larger number of parameters that need to be determined.…”