Estimation of the thickness and the optical parameters of several stacked thin films using optimization

Andrade, Ricardo; Birgin, Ernesto G.; Chambouleyron, I.; Martínez, José Mário; Ventura, Sérgio Drumond

doi:10.1364/ao.47.005208

Cited by 15 publications

(10 citation statements)

References 18 publications

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“…The single homogenous absorbing layer model is only an approximation, since it does not consider either the existence of the substrate/film interface, the surface roughness, or oxidation. We can expect that the error of determination of increases extremely for < 30 nm [54,55]. The relative error in the thickness determination is independent of for layers with > 70 nm (±0.3%), and downwards it increases up to 1% for layers with d∼30 nm.…”

Section: Resultsmentioning

confidence: 93%

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

Todorov

Tasseva

Lozanova

et al. 2013

Advances in Condensed Matter Physics

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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).

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Section: Resultsmentioning

confidence: 93%

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

Todorov

Tasseva

Lozanova

et al. 2013

Advances in Condensed Matter Physics

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“…The optical constants (refractive index and absorption coefficient) of both flat and structured VO 2 ‐polymer composite films at low and high temperature were estimated through PUMA from the one‐film system by using experimental transmittance data. [ 52,53 ] The PUMA software is freely available from the PUMA Project web page (https://www.ime.usp.br/~egbirgin/puma/#related). A 2D FDTD (Lumerical Solutions, Inc.) method was used to calculate transmittance of the VO 2 ‐polymer composite thin film and tilted VO 2 ‐polymer composite structure at low and high temperature.…”

Section: Methodsmentioning

confidence: 99%

3D Printed Smart Windows for Adaptive Solar Modulations

Zhou

Tan

et al. 2020

Advanced Optical Materials

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Vanadium dioxide (VO2) based thermochromic smart window is considered as the most promising approach for economizing building energy consumption. However, the high phase transition temperature (τc), low luminous transmission (Tlum), and solar modulation (ΔTsol) impose an invertible challenge for commercialization. Currently, smart window research surprisingly assumes that the sunlight radiates in one direction which is obviously not valid as most regions receive solar radiation at various angles in different seasons. For the first time, solar elevation angle is considered and 3D printing technology is employed to fabricate tilted microstructures for modulating solar transmission dynamically. To maximize energy‐saving performance, the architecture of the structures (tilt, thickness, spacing, and width) and tungsten (W) doped VO2 can be custom‐designed according to the solar elevation angle variation at the midday between seasons and tackle the issue of compromised Tlum and ΔTsol with W‐doping. The energy consumption simulations in different cities prove the efficiency of such dynamic modulation. This first attempt to adaptively regulate the solar modulation by considering the solar elevation angle together with one of the best reported thermochromic properties (τc = 40 °C, Tlum(average) = 40.8%, ΔTsol = 23.3%) may open a new era of real‐world‐scenario smart window research.

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“…(6)] is [−π, π] rad/sample [24]. The angular optical frequency vector can be written as ω[m] = ω min + m δ ω.…”

Section: A3 Depth Range Of the Spectrometermentioning

confidence: 99%

“…Unlike QPI which uses the field phase for measuring the optical thickness, several methods relying on the reflectance and transmittance were used. Andrade et al [6] used optimization applied to transmittance measurements for determining submicron thickness of a thin film stack. Reflectometry uses broad bandwidth reflectance to retrieve the thicknesses of thin films, using models requiring a priori knowledge about the refractive indices of the different layers of the samples under study [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Super-resolved thickness maps of thin film phantoms and in vivo visualization of tear film lipid layer using OCT

Santos

Schmetterer²,

Triggs

et al. 2016

Biomed. Opt. Express

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In optical coherence tomography (OCT), the axial resolution is directly linked to the coherence length of the employed light source. It is currently unclear if OCT allows measuring thicknesses below its axial resolution value. To investigate spectral-domain OCT imaging in the super-resolution regime, we derived a signal model and compared it with the experiment. Several island thin film samples of known refractive indices and thicknesses in the range 46 − 163 nm were fabricated and imaged. Reference thickness measurements were performed using a commercial atomic force microscope. In vivo measurements of the tear film were performed in 4 healthy subjects. Our results show that quantitative super-resolved thickness measurement can be performed using OCT. In addition, we report repeatable tear film lipid layer visualization. Our results provide a novel interpretation of the OCT axial resolution limit and open a perspective to deeper extraction of the information hidden in the coherence volume.

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Estimation of the thickness and the optical parameters of several stacked thin films using optimization

Cited by 15 publications

References 18 publications

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

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

3D Printed Smart Windows for Adaptive Solar Modulations

Super-resolved thickness maps of thin film phantoms and in vivo visualization of tear film lipid layer using OCT

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