Characterization of zirconia– and niobia–silica mixture coatings produced by ion-beam sputtering

Abstract

ZrO2-SiO2 and Nb2O5-SiO2 mixture coatings as well as those of pure zirconia (ZrO2), niobia (Nb2O5), and silica (SiO2) deposited by ion-beam sputtering were investigated. Refractive-index dispersions, bandgaps, and volumetric fractions of materials in mixed coatings were analyzed from spectrophotometric data. Optical scattering, surface roughness, nanostructure, and optical resistance were also studied. Zirconia-silica mixtures experience the transition from crystalline to amorphous phase by increasing the content of SiO2. This also results in reduced surface roughness. All niobia and silica coatings and their mixtures were amorphous. The obtained laser-induced damage thresholds in the subpicosecond range also correlates with respect to the silica content in both zirconia- and niobia-silica mixtures.

Electronic quantization in dielectric nanolaminates

“…Also, the damage process in the USP-regime was demonstrated to be dependent on the electronic properties of the involved dielectric materials [4]. In previous investigations [1][2][3][4] the content of silica was varied in ternary compounds with different high refractive index materials. In these experiments, an increase of the silica content directly induced a blue shift of the band gap energy and gain of the LIDT-value of the compound material.…”

“…Especially on the basis of ternary composites, both, the index of refraction as well as the band gap energy can be tuned in range between the values of the pure materials [1]. These mixtures were applied in different concepts to improve the laser damage thresholds of optical coating systems.…”

Assessment of effective-medium theories of ion-beam sputtered Nb₂O₅–SiO₂ and ZrO₂–SiO₂ mixtures

“…For an oxygen element, all models showed the ratio within 4%. A pure zirconia sample also has a poly-crystalline nano-structure, while other samples are amorphous [19]. Mixing zirconia in different phases with silica may result in additional discrepancies when using EMA models.…”

“…All the samples were measured in previous investigation by X-ray diffraction, angle-resolved and total integrated scattering, atomic force microscopy, and laser-induced damage threshold methods [19]. In addition, spectrophotometric data were also obtained.…”

Optical breakdown of multilayer thin-films induced by ultrashort pulses at MHz repetition rates

“…This fact has motivated extensive studies of ultrashort-pulseinduced optical breakdown of thin-films over the last decade [1][2][3][4][5][6]. All of them have been carried out by measuring the damage threshold at a low average power, either in single-shot mode or by using a pulse train at a kHz repetition rate.…”