scholarly journals Optical Properties of Colored Colloidal Systems. II. Apparent Refractive Index and Extinction Coefficient of the System of Small Spherical Particles

1961 ◽  
Vol 34 (3) ◽  
pp. 433-436 ◽  
Author(s):  
Masayuki Nakagaki ◽  
Tomiko Fujii
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Extinction Coefficient ◽  
Spherical Particles ◽  
Colloidal Systems

Composition Effect of Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulphonic Acid) and Polyaniline to Dispersion and Optical Properties of Polymer Blends

2016 ◽  
Vol 846 ◽  
pp. 225-229 ◽  
Author(s):  
N.F.M. Sahapini ◽  
Ahmad Nazib Alias ◽  
Z.M. Zabidi ◽  
Mohd Ashmir Yahya
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Polymer Blends ◽  
Photon Energy ◽  
Extinction Coefficient ◽  
Sulphonic Acid ◽  
Optical Parameters ◽  
Normal Dispersion ◽  
Casting Technique ◽  
Optical Dielectric

A Polymer blends compose of Poly (3,4-ethylenedioxythiophene):Poly (styrene sulphonic acid)(PEDOT:PSS) and Polyaniline (PANi) have been prepared using drop casting technique. Optical parameters such as refractive index (n), extinction coefficient (k), reflectance, and optical dielectric were determined in this study. It is found that reflectance spectra increase as the PANi concentration decreases in the sample of small photon energy. The refractive index of the sample shows significant effect with the PEDOT:PSS concentration. As the concentration of PEDOT:PSS increases, the refractive index shows a normal dispersion behavior. Extinction coefficient decrease as the wavelength increase within the range of 300 nm to 350 nm that may contribute to the loss fraction of light due to scattering and the decreasing of absorbance at this range. However, the extinction coefficient increases from 350 nm to the maximum wavelength of 800 nm since the absorbance is also increasing. Both the real and imaginary part of the dielectric constant decreases when the photon energy increases. This revealed that the compositions of PEDOT:PSS influence the optical properties of hybrid PEDOT-PSS:PANi thin film.

scholarly journals The influence of dust optical properties on the colour of simulated MSG-SEVIRI Desert Dust infrared imagery

2018 ◽  
Vol 18 (13) ◽  
pp. 9681-9703 ◽  
Author(s):  
Jamie R. Banks ◽  
Kerstin Schepanski ◽  
Bernd Heinold ◽  
Anja Hünerbein ◽  
Helen E. Brindley
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Particle Shape ◽  
Transport Model ◽  
Mineral Dust ◽  
Spherical Particles ◽  
Upper And Lower Bounds ◽  
Infrared Imagery ◽  
Desert Dust ◽  
Infrared Extinction

Abstract. Satellite imagery of atmospheric mineral dust is sensitive to the optical properties of the dust, governed by the mineral refractive indices, particle size, and particle shape. In infrared channels the imagery is also sensitive to the dust layer height and to the surface and atmospheric environment. Simulations of mineral dust in infrared Desert Dust imagery from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) have been performed, using the COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdelling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model) dust transport model and the Radiative Transfer for TOVS (RTTOV) program, in order to investigate the sensitivity of the imagery to assumed dust properties. This paper introduces the technique and performs initial validation and comparisons with SEVIRI measurements over North Africa for daytime hours during 6 months covering June and July of 2011–2013. Using T-matrix scattering theory and assuming the dust particles to be spherical or spheroidal, wavelength- and size-dependent dust extinction values are calculated for a number of different dust refractive index databases, along with several values of the particle aspect ratio, denoting the particle shape. The consequences for the infrared extinction values of both the particle shape and the particle orientation are explored: this analysis shows that as the particle asphericity increases, the extinctions increase if the particles are aligned horizontally, and decrease if they are aligned vertically. Randomly oriented spheroidal particles have very similar infrared extinction properties as spherical particles, whereas the horizontally and vertically aligned particles can be considered to be the upper and lower bounds on the extinction values. Inputting these values into COSMO-MUSCAT-RTTOV, it is found that spherical particles do not appear to be sufficient to describe fully the resultant colour of the dust in the infrared imagery. Comparisons of SEVIRI and simulation colours indicate that of the dust types tested, the dust refractive index dataset produced by Volz (1973) shows the most similarity in the colour response to dust in the SEVIRI imagery, although the simulations have a smaller range of colour than do the observations. It is also found that the thermal imagery is most sensitive to intermediately sized particles (radii between 0.9 and 2.6 µm): larger particles are present in too small a concentration in the simulations, as well as with insufficient contrast in extinction between wavelength channels, to have much ability to perturb the resultant colour in the SEVIRI dust imagery.

scholarly journals Studies on Aerosol Optical Properties at High Altitude Station in Western Himalayas Using Raman Lidar

2020 ◽  
Vol 237 ◽  
pp. 02034
Author(s):  
Shishir Kumar Singh ◽  
Jaswant ◽  
S.R. Radhakrishnan ◽  
Davender Sethi ◽  
Chhemendra Sharma
Keyword(s):  
Optical Properties ◽  
Extinction Coefficient ◽  
Spherical Particles ◽  
Western Himalayas ◽  
Depolarization Ratio ◽  
Raman Lidar ◽  
Inversion Algorithm ◽  
Backscatter Coefficient ◽  
Aerosol Optical Properties ◽  
Linear Depolarization Ratio

The aerosol optical properties have been investigated using the Raman lidar system for the month of November 2018 at the western Himalayan station of Palampur. Before deriving the optical properties, the lidar data has been applied with initial pre-processing such as Dead time correction, atmospheric noise correction, temporal and spatial averaging, range correction, gluing etc. The optical properties such as backscatter coefficient, extinction coefficient and linear depolarization ratio have been derived by using the inversion algorithm proposed by Fernald. The results show that the backscatter coefficient was found in the range from 9.00E-9 m−1sr−1 to 4.97E-6 m−1sr−1 and the extinction coefficient was found in the range from 3.16E-7m-1 to 1.74E-4m-1. The Linear depolarization ratio was in the range from 0.0179 to 0.621 with lower values at near heights suggesting the dominance of spherical particles at the lower heights. We have also observed a cloud layer at a height of 9.5 km to 12.1 km with high depolarization ratio during the observation period on 22/11/2018.

The Optical Properties of DLC Films Processed by Laser Radiation

2011 ◽  
Vol 337 ◽  
pp. 120-124
Author(s):  
Yin Feng Chen ◽  
Jun Qi Xu ◽  
Jun Hong Su ◽  
Ling Xia Han
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Laser Radiation ◽  
Extinction Coefficient ◽  
Laser Energy ◽  
Damage Threshold ◽  
Laser Damage Threshold ◽  
Laser Damage ◽  
The Real ◽  
Before And After

Diamond-like carbon (DLC) films have being widely applied in various domains owing to their excellent optical and mechanical properties, chemical inertness and bio-compatibility[1,2]. But it generally exhibits low a laser induced damage threshold (LIDT).As to infrared protective films, DLC films were asked to be a high laser damage threshold. So far, the real reason of laser damage is unclear. In order to understand the real reason of the laser damage, it is necessary to deeply research the relationship between optical properties and laser radiation. In this paper, optical properties post irraditing by various laser energy were inverstigated. Hydrogen-free amorphous carbon films were deposited by unbalanced magnetron sputtering with a graphite target on Si substrate in this paper. The DLC films were radiated with raster scans methods by a 1064nm and 8–10 ns laser in this work. The transmittance, refractive index, extinction coefficient and surface morphology of DLC before and after radiation were examined by fourier transform infrared spectrometer, ellipsometer and talysurf respectively. The influences were considered as function of laser energy density.The optical properties before and after laser radiation were compared. It is found that as laser fluences rise from 0 to 0.5 J/cm2, the transmittance peak reduce from 67.06% to 58.27%, the refractive index decrease from 1.88 to 1.67(λ=1200), the extinction coefficient increase from 0.07 to 0.32(λ=1200), and the surface roughness become 149.28nm in this procedλure. Especially, the reasons of change were expounded in this paper.

Theoretical analysis on the development of opaque fibers based on Mie scattering

2012 ◽  
Vol 83 (4) ◽  
pp. 355-362 ◽  
Author(s):  
Ni Wang ◽  
Wenyan Pan ◽  
Meiwu Shi ◽  
Jianyong Yu
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Extinction Coefficient ◽  
Incident Light ◽  
Mie Scattering ◽  
Spherical Particles ◽  
Diameter Distribution ◽  
Matlab Program ◽  
Mie Scattering Theory ◽  
First Time

Mie scattering theory has been widely used to solve the problem of light scattering by single spherical particles in many fields. In this article, it was applied for the development of opaque fiber for the first time. Firstly, the spheroid particles were simplified as equivalent spherical particles. Then, the extinction coefficient was calculated using the Matlab program and the influences of the size parameter, refractive index and the wavelength of the incident light on the extinction coefficient were discussed in detail. Finally, the results indicated that the extinction coefficient depended greatly on the dimension and the refractive index of the particles, and also the wavelength of the incident light. For the development of the opaque fiber, it would be better to choose particles that had the higher refractive index and a certain diameter distribution to achieve the most effective light scattering.

scholarly journals Effect of Annealing Temperature in Improvement the Optical Properties of TiO2 Doped Fe2O3 to Use in Thin Film

2019 ◽  
pp. 1-12
Author(s):  
Abubakr Mahmoud Hamid ◽  
Hassan Wardi Hassan ◽  
Fatima Ahmed Osman
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Iron Oxide ◽  
Titanium Oxide ◽  
Extinction Coefficient ◽  
Tio2 Thin Film ◽  
Annealing Temperature ◽  
Spray Pyrolysis Deposition

Solar energy is already has being widely successfully used in residential and industrial setting for thermal and electrical application such as space technology, communication, etc. I. Aims: The aim of this study the effect of the annealing temperature in improvement optical properties of titanium oxide nanostructure doped iron oxide for use in thin film. Study Design: The spray pyrolysis deposition method used for preparation the nanostructure material. Place and Duration of Study: This study was conducted in department of physics and department of materials sciences, Al-Neelain University, between January 2016 and January 2019.  Methodology: Thin films of Titanium Oxide (TiO2) doped Iron Oxide (Fe2O3) have been prepared by chemical spray pyrolysis deposition technique. A laboratory designed glass atomizer was used for spraying the aqueous solution. Which has an output nozzle about 1 mm. then film were deposited on preheated cleaned glass substrates at temperature of 400°C. we used different concentration to study optical parameters. A 1.5 g TiO2 powder of anatase structure doped with 1.5 g of Fe2O3 was mixed with 2 ml of ethanol and stirred using a magnetic stirrer for 30 minutes to form TiO2 paste to obtain the starting solution for deposition and spray time was 10 s and spray interval 2 min was kept constant. The carrier gas (filtered compressed air) was maintained at a pressure of 105 Nm-2, and distance between nozzle and substrate was about 30 cm ± 1 cm. Thickness of sample was measured using the weighting method and was found to be around 400nm. Optical transmittance and absorbance were record in wavelength range of (200-1100) nm using UV-Visible spectrophotometer (Shimadzu Company Japan). Results: The results obtained showed that the optical band gap decreased from 5.6eV before annealing to (3.9, 3.26, 3.24 and 3.27 eV) after annealing temperature at(450° – 500°) for TiO2:Fe2O3 thin films, this result refer to the broadening of  secondary levels that product by TiO2: doping to the Fe2O2thin films. Also the results showed the variation of refractive index with wavelength for different concentration after annealing temperature at (450° – 500°) of TiO2: Fe2O3 films from this figure, it is clear that n decrease with low concentration and increase with high concentration after annealing temperature that mean the density is decreased of this films. In addition the extinction coefficient of TiO2:Fe2O3 thin films recorded before annealing and with different concentration (1.1, 1.2, 1,5 and 1,6) and in the range of (300 – 1200) nm and at annealing temperature from (450° – 500°). It observed from that the extinction coefficient, decrease sharply with the increase of wavelength for all prepared films and all the sample after annealing is interference between them accept the sample before annealing is far from the other sample. Conclusion: The TiO2 thin film shows better result after annealing; By exposing temperature during annealing process degree at (450o- 500o) is found to be the best temperature for annealing TiO2 thin film. The study concluded that an annealing temperature Contributes to the improvement of optical properties related to increasing the efficiency of the solar cell, especially the refractive index, energy gap, extinction coefficient.

scholarly journals Structural and optical properties for PVA- PEG-MnCl2 composites

2019 ◽  
Vol 15 (32) ◽  
pp. 99-113
Author(s):  
Mahdi Hasan Suhail
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Polymer Blend ◽  
Extinction Coefficient ◽  
Energy Gap ◽  
Dielectric Constants ◽  
Structural And Optical Properties ◽  
Optical Energy Gap ◽  
X Ray ◽  
Amorphous Structures

Polymer films of PEG and PVA and their blend with differentconcentrations of MnCl2 (0, 2, 4, 6 and 10 %.wt) were study usingcasting technique. The X-ray spectra of pure PEG, PVA andPVA:PEG films and with addition of 2% concentrations from(MnCl2) show amorphous structures. The results for FTIR show theinteraction between the filler and polymer blend results indecreasing crystallinity with rich amorphous phase. Thisamorphous nature confirms the complexation between the filler andthe polymer blend. The optical properties of (PVA:PEG/MnCl2)contain the recording of absorbance (A) and explain that theabsorption coefficient (α), refractive index (n), extinction coefficient(ko) and the dielectric constants (real and imaginary part) increasewith increasing the concentration of Composite (PVA:PEG/MnCl2).The optical energy gap for electrons transitions both are direct andindirect allowed.

An ab-initio study of electronic and optical properties of RhXO3 (X = Ga, Ag) perovskites

2022 ◽  
Author(s):  
Syed Awais Rouf ◽  
Muhammad Iqbal Hussain ◽  
Umair Mumtaz ◽  
Hafiz Tariq Masood ◽  
Hind Albalawi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Energy Loss ◽  
Ab Initio ◽  
Loss Function ◽  
Extinction Coefficient ◽  
Ab Initio Study ◽  
Band Formation ◽  
Optical Behavior

Abstract The ab-initio computations were performed to study the electronic and optoelectronic properties of RhXO3 (X = Ga, Ag) using WIEN2k code. The RhGaO3 has band gap of 2.29 eV, and the behavior of RhAgO3 metallic. The sub-TDOS of the studied materials revealed that rhodium and oxygen atoms have significant contributions in the valence band and conduction band formation of both materials. The silver cation is responsible for the reasonable peaks appearing at the Fermi level of RhAgO3, which demonstrated the conducting nature of RhAgO3. The dielectric functions, optical conductivity, energy loss function, absorption coefficient, refractive index, extinction coefficient, and reflectivity are computed for these materials to understand the optical behavior of the studied materials. The analysis of optical properties ensure the RhGaO3 is a promising material for optoelectronics while RhAgO3 has metallic nature.

scholarly journals The influence of dust optical properties on the colour of simulated MSG-SEVIRI Desert Dust imagery

2018 ◽  
Author(s):  
Jamie R. Banks ◽  
Kerstin Schepanski ◽  
Bernd Heinold ◽  
Anja Hünerbein ◽  
Helen E. Brindley
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Particle Shape ◽  
Transport Model ◽  
Mineral Dust ◽  
Atmospheric Environment ◽  
Spherical Particles ◽  
Dust Particles ◽  
Small Scale ◽  
Desert Dust

Abstract. Satellite imagery of atmospheric mineral dust is sensitive to the optical properties of the dust, governed by the mineral refractive indices, particle size, and particle shape. In infrared channels the imagery is also sensitive to the dust layer height and to the surface and atmospheric environment. Simulations of mineral dust in infrared Desert Dust imagery from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) have been performed, using the COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdelling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model) dust transport model and the Radiative Transfer for TOVS (RTTOV) program, in order to investigate the sensitivity of the imagery to assumed dust properties. This paper introduces the technique and performs initial validation and comparisons with SEVIRI measurements over North Africa for daytime hours during the six months of the Junes and Julys of 2011–2013. Using T-matrix scattering theory and assuming the dust particles to be spherical or spheroidal, wavelength- and size-dependent dust extinction values are calculated for a number of different dust refractive index databases, along with several values of the particle aspect ratio, denoting the particle shape. It is found that spherical particles do not appear to be sufficient to describe fully the resultant colour of the dust in the infrared imagery. Comparisons of SEVIRI and simulation colours indicate that of the dust types tested, the dust refractive index dataset produced by Volz (1973) shows the most similarity in the colour response to dust in the SEVIRI imagery, although the simulations have a smaller range of colour than do the observations. It is also found that the thermal imagery is most sensitive to intermediately sized particles (radii between 0.9 and 2.6 μm): larger particles are present in too small a concentration in the simulations, as well as with insufficient contrast in extinction between wavelength channels, to have much ability to perturb the resultant colour in the SEVIRI dust imagery.

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