Fabrication of Ultralow Stress TiO2/SiO2 Optical Coatings by Plasma Ion-Assisted Deposition

Guo, Chaowei; Kong, Mingdong

doi:10.3390/coatings10080720

Cited by 20 publications

(10 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Luckely, SiO 2 layers usually show a built-in compressive stress, whereas TiO 2 layers show a built-in tensile stress 31 , so that they act in compensation when the SiO 2 /TiO 2 multilayer is deposited. Moreover, by depositing the structure at a specific temperature or treating it with postdeposition annealing cycles, the total built-in stress can be reduced to values lower than 5 MPa 30 . Thermal gradients produce additional stress that adds to the built-in stress.…”

Section: Resultsmentioning

confidence: 99%

Multilayers for directed energy accelerated lightsails

et al. 2022

View full text Add to dashboard Cite

A lightsail accelerated via directed energy is a candidate technology to send a probe into the deep space in a time period compatible with human life. The light emitted by a ground-based large-aperture phased laser array is directed onto the lightsail to produce a thrust by transferring the momentum of the incident photons. Here we demonstrate that optimized multilayer structures allow ultralight spacecraft being accelerated by laser radiation pressure up to 20% of the light velocity, and eventually even above, as long as a compromise between efficiency and weight is achieved. Layer materials are selected to provide high reflectance in the Doppler-shifted laser wavelength range as well as high emissivity in the infrared, this last characteristic being required to survive to the temperature increase during the acceleration phase.

show abstract

Section: Resultsmentioning

confidence: 99%

Multilayers for directed energy accelerated lightsails

et al. 2022

View full text Add to dashboard Cite

show abstract

“…From the absorbance (A) obtained from spectrophotometer, other properties such as transmittance, extinction coefficient and band gap were calculated. Transmittance (T) was determine using equation (7) as given by [30,31].…”

Section: Optical Propertiesmentioning

confidence: 99%

Effect of SILAR Cycles on the Thickness, Structural, Optical Properties of Cobalt Selenide Thin Films

N.J

V.C²,

Okoli

et al. 2021

Int. Res. J. multidiscip. Technovation

View full text Add to dashboard Cite

Cobalt Selenide thin films were fabricated using Successive Ionic Layer Adsorption and Reaction (SILAR) deposition technique at different SILAR cycles. The precursors for Cobalt and Selenium ions were CoCl2.6H2O and Na2SeSO3 respectively. Optical properties and thickness of the deposited films were studied to determine the effect of number of SILAR cycles on these properties. The optical absorbance of the films was found to decrease as wavelength increases and increases as SILAR cycle increases. Transmittance of the CoSe thin films was found to increase as the wavelength increases but decreases as number of SILAR cycles increased. The extinction coefficient of CoSe thin films decreases as wavelength increases but increases as the SILAR cycles increases. The energy band gap of CoSe thin films deposited decreases from 2.47 eV to 2.20 eV as number of SILAR cycles increases and film thickness increases from 92.96 nm and 225.63 nm. Structural properties of deposited cobalt selenide thin films showed that they correspond to orthorhombic phase of CoSe2 crystal structure of cobalt selenide thin films with crystallite size ranging from 7.63 nm to 13.07 nm.

show abstract

“…Deposition of thin film of TiO 2 on glass substrate using electron beam evaporation causes tensile residual stress in the order of 170 MPa [ 38 ]. While deposition of thin film of SiO 2 on a thin film of TiO 2 causes a compression stress in the same order to form [ 39 , 40 ]. Deposition of silver on the other hand causes a tensile stress in the order of 18 Pa which gives a radius of curvature in the range of thousands of kilometers according to Stoney’s equation [ 38 ].…”

Section: Device Designmentioning

confidence: 99%

Electrostatically Tuned Optical Filters Based on Hybrid Plasmonic-Dielectric Thin Films for Hyperspectral Imaging

et al. 2021

View full text Add to dashboard Cite

Hyperspectral imaging has a wide range of uses, from medical diagnostics to crop monitoring; however, conventional hyperspectral imaging systems are relatively slow, bulky, and rather costly. In this paper, we present an inexpensive, compact tunable optical filter for hyperspectral applications. The filter is based on a Fabry-Pérot interferometer utilizing hybrid metallic-dielectric mirrors and actuated using a MEMS electrostatic actuator. The optical filter is designed using the transfer matrix method; then, the results were verified by an electromagnetic wave simulator. The actuator is based on a ring-shaped parallel plate capacitor and is designed using COMSOL Multiphysics. An actuation displacement of 170 nm was used, which is the required distance to tune the filter over the whole visible range (400–700 nm). There are two designs proposed for the optical filter: the first was optimized to provide maximum transmission and the other is optimized to have minimum full-width-half-maximum (FWHM) value. The first design has a maximum transmission percentage of 94.45% and a minimum transmission of 86.34%; while the minimum FWHM design had an average FWHM value of 7.267 nm. The results showed improvements over the current commercial filters both in transmission and in bandwidth.

show abstract

Fabrication of Ultralow Stress TiO2/SiO2 Optical Coatings by Plasma Ion-Assisted Deposition

Cited by 20 publications

References 34 publications

Multilayers for directed energy accelerated lightsails

Multilayers for directed energy accelerated lightsails

Effect of SILAR Cycles on the Thickness, Structural, Optical Properties of Cobalt Selenide Thin Films

Electrostatically Tuned Optical Filters Based on Hybrid Plasmonic-Dielectric Thin Films for Hyperspectral Imaging

Contact Info

Product

Resources

About