scholarly journals Determining the optical properties of blood using He-Ne laser and double integrating sphere set-up

2019 ◽  
Vol 25 (1) ◽  
pp. 1-5
Author(s):  
Habib E. Ashoor ◽  
Khalil Ebrahim Jasim

Abstract The behaviour of light interaction with biological tissue is determined by micro-optical parameters: refractive index (n), absorption coefficient (µa), scattering coefficient (µs), and anisotropy (g). The goal of this study is to measure the optical properties of normal whole blood using He-Ne laser (wavelength 632.8 nm). The refractive index is measured using the traveller microscope. The integrating sphere method is used to measure the macro-optical parameters: total diffusive reflectance, transmittance, and collimated transmittance at wavelength 632.8 nm. The macro-optical parameters are fed to Inverse Adding Doubling (IAD) theoretical technique, to estimate the micro-optical parameters (µs, µa, g). An alternative practical method is used to measure the g value based on utilising the goniometric table. The study reveals that the refractive index (n) equals 1.395±0.0547, absorption coefficient (µa) equals 2.37 mm−1, scattering coefficient (µs) equals 55.69 mm−1, and anisotropy (g) equals 0.82. In conclusion, these findings approved, in general, the applicability of the suggested experimental set up. The set up depend on using three devices: the integrating sphere method to estimate (µs, µa, g), traveller microscope (n) and goniometer (g).

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Shahin ◽  
Wesam Bachir ◽  
Moustafa Sayem El-Daher

The optical properties of 1 μm polystyrene in the wavelength range of 500–750 nm were estimated by using a white light spectrophotometric transmittance spectroscopy and a single integrating sphere system. To retrieve the optical characteristics, two analytical methods, namely, diffusion approximation and Kubelka–Munk were used, and then their results were compared with Mie theory calculations. The correspondence of the Kubelka–Munk scattering coefficient with Mie was obvious, and relative errors varied between 6.73% and 2.66% whereas errors varied between 6.87% and 3.62% for diffusion theory. Both analytical methods demonstrated the absorption property of polystyrene over the abovementioned wavelength range. Although absorption coefficient turned out to be much lower than scattering, constructing a realistic optical phantom requires taking into account absorption property of polystyrene. Complex refractive index of polystyrene based on these two methods was determined. Inverse Mie algorithm with scattering coefficient was also used to retrieve the real part of refractive index and absorption coefficient for calculating the imaginary part of refractive index. The relative errors of the real part did not exceed 2.6%, and the imaginary part was in consistence with the prior works. Finally, the presented results confirm the validity of diffusion theory with a single integrating sphere system.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1570
Author(s):  
Shujahadeen B. Aziz ◽  
Elham M. A. Dannoun ◽  
Dana A. Tahir ◽  
Sarkawt A. Hussen ◽  
Rebar T. Abdulwahid ◽  
...  

In the current study, polymer nanocomposites (NCPs) based on poly (vinyl alcohol) (PVA) with altered refractive index and absorption edge were synthesized by means of a solution cast technique. The characterization techniques of UV–Vis spectroscopy and XRD were used to inspect the structural and optical properties of the prepared films. The XRD patterns of the doped samples have shown clear amendments in the structural properties of the PVA host polymer. Various optical parameters were studied to get more insights about the influence of CeO2 on optical properties of PVA. On the insertion of CeO2 nanoparticles (NPs) into the PVA matrix, the absorption edge was found to move to reduced photon energy sides. It was concluded that the CeO2 nanoparticles can be used to tune the refractive index (n) of the host polymer, and it reached up to 1.93 for 7 wt.% of CeO2 content. A detailed study of the bandgap (BG) was conducted using two approaches. The outcomes have confirmed the impact of the nanofiller on the BG reduction of the host polymer. The results of the optical BG study highlighted that it is crucial to address the ɛ” parameter during the BG analysis, and it is considered as a useful tool to specify the type of electronic transitions. Finally, the dispersion region of n is conferred in terms of the Wemple–DiDomenico single oscillator model.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1648
Author(s):  
Muaffaq M. Nofal ◽  
Shujahadeen B. Aziz ◽  
Jihad M. Hadi ◽  
Wrya O. Karim ◽  
Elham M. A. Dannoun ◽  
...  

In this work, a green approach was implemented to prepare polymer composites using polyvinyl alcohol polymer and the extract of black tea leaves (polyphenols) in a complex form with Co2+ ions. A range of techniques was used to characterize the Co2+ complex and polymer composite, such as Ultraviolet–visible (UV-Visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The optical parameters of absorption edge, refractive index (n), dielectric properties including real and imaginary parts (εr, and εi) were also investigated. The FRIR and XRD spectra were used to examine the compatibility between the PVA polymer and Co2+-polyphenol complex. The extent of interaction was evidenced from the shifts and change in the intensity of the peaks. The relatively wide amorphous phase in PVA polymer increased upon insertion of the Co2+-polyphenol complex. The amorphous character of the Co2+ complex was emphasized with the appearance of a hump in the XRD pattern. From UV-Visible spectroscopy, the optical properties, such as absorption edge, refractive index (n), (εr), (εi), and bandgap energy (Eg) of parent PVA and composite films were specified. The Eg of PVA was lowered from 5.8 to 1.82 eV upon addition of 45 mL of Co2+-polyphenol complex. The N/m* was calculated from the optical dielectric function. Ultimately, various types of electronic transitions within the polymer composites were specified using Tauc’s method. The direct bandgap (DBG) treatment of polymer composites with a developed amorphous phase is fundamental for commercialization in optoelectronic devices.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1225
Author(s):  
Ali Atta ◽  
Mostufa M. Abdelhamied ◽  
Ahmed M. Abdelreheem ◽  
Mohamed R. Berber

In order to potentiate implementations in optical energy applications, flexible polymer composite films comprising methyl cellulose (MC), polyaniline (PANI) and silver nanoparticles (AgNPs) were successfully fabricated through a cast preparation method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating a successful incorporation of AgNPs into the MC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNPs into the MC/PANI blend. The optical parameters such as band gap (Eg), absorption edge (Ed), number of carbon cluster (N) and Urbach energy (Eu) of pure MC polymer, MC/PANI blend and MC/PANI/Ag films were determined using the UV optical absorbance. The effects of AgNPs and PANI on MC polymer linear optical (LO) and nonlinear optical (NLO) parameters including reflection extinction coefficient, refractive index, dielectric constant, nonlinear refractive index, and nonlinear susceptibility are studied. The results showed a decrease in the band gap of MC/PANI/AgNPs compared to the pure MC film. Meanwhile, the estimated carbon cluster number enhanced with the incorporation of the AgNPs. The inclusion of AgNPs and PANI has enhanced the optical properties of the MC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications.


2021 ◽  
pp. 089270572110386
Author(s):  
Ali F Al-Shawabkeh ◽  
Ziad M Elimat ◽  
Khaleel N Abushgair

The goal of this study was to investigate the optical properties of the prepared polyvinyl chloride (PVC)/zinc oxide (ZnO) nanocomposite films. The PVC/ZnO nanocomposite films consist of the addition of different concentrations with both non-annealed ZnO nanoparticles and ZnO nanoparticles annealed at temperature of 700°C. The PVC/ZnO nanocomposite films by weight concentrations of (0 wt.%, 2.5 wt.%, 5 wt.% and 10 wt.%) have been prepared by the casting method. The optical absorbance and transmittance values of the composites films were measured in the wavelength range between (250 to 1100 nm) at room temperature by using the UV-1800 Shimadzu spectrophotometer. The optical properties (absorption coefficient, dielectric constant, refractive index, and optical conductivity) have been investigated by the ultraviolet (UV) spectrophotometer. The optical parameters (direct optical energy gap, excitation energy for electronic transitions, the dispersion energy, static refractive index, static dielectric constant, optical oscillator strengths, the moments of optical spectrum, linear optical susceptibility, third-order nonlinear optical susceptibility, nonlinear refractive index, high-frequency dielectric constant, the carrier concentration to the effective mass ratio, the long wavelength refractive index and the plasma frequency) were calculated. The results showed that the optical properties behavior of the PVC/ZnO nanocomposite films was found to be dependent on the ZnO concentration, and photon wavelength. In addition, the results of the study show that the optical parameters can be influenced by alter the concentration of the nonannealed and annealed a ZnO nanoparticle in the PVC polymer matrix.


2021 ◽  
Vol 900 ◽  
pp. 16-25
Author(s):  
Tabarak Mohammed Awad ◽  
May A.S. Mohammed

In this study, some optical properties were studied of the pure vinyl polyvinyl alcohol (PVA) nanopolymer (German origin). Under the influence of different temperatures and pressures of PVA. Where 25 samples were prepared for the purpose of conducting the research. Which studied the study of these samples was done by recording the absorbance and transmittance spectra of the wavelengths (200-900) nm. From them, absorbance, transmittance, reflectivity, absorption coefficient, refractive index, extinction coefficient, complex dielectric constant were calculated. At different temperatures (25,40, 80, 120, 160)°C. And with different pressures within the range (7.5,8,8.5,9,9.5) MPa. The results are that the permeability of the polymer (PVA) at different temperatures for each pressure decreases with increasing temperature, and that all other calculated optical properties increase with increasing temperature.


2010 ◽  
Vol 19 (03) ◽  
pp. 427-436
Author(s):  
A. MENDOZA-GARCÍA ◽  
A. ROMERO-DEPABLOS ◽  
M. A. ORTEGA ◽  
J. L. PAZ ◽  
L. ECHEVARRÍA

We have developed an analytical method to describe the optical properties of nanoparticles, whose results are in agreement with the observed experimental behavior according to the size of the nanoparticle under analysis. Our considerations to describe plasmonic absorption and dispersion are based on the combination of the two-level molecular system and the two-dimensional quantum box models. Employing the optical stochastic Bloch equations, we have determined the system's coherence, from which we have calculated expressions for the absorption coefficient and refractive index. The innovation of this methodology is that it allows us to take into account the solvent environment, which induce quantum effects not considered by classical treatments.


2018 ◽  
Vol 26 (10) ◽  
pp. 249-256
Author(s):  
Waleed Khalid Kadhim

In this paper I present the preparation of (Sb2o3) thin films using thermal evaporation in vacuum, procedure with different thickness  (100 ,150 ,200 ,and 250) nm, by using ( hot plate) from Molybdenum matter at temperature in ( 9000c) and the period of time (15mint) ,the prepared in a manner thermal evaporation in a vacuum and precipitated on glass bases, pure Antimony Trioxide (sb2o3 ) thin films with various condition have been successfully deposited by (T.E.V) on glass slide substrates. The substrates temperature of about 100oC and the vacuum of about 10-6 torr, to investigated oxidation of evaporated, measure spectra for prepared films in arrange of wavelength (250 – 1100 nm). The following optical properties have been calculated: the absorption coefficient, the forbidden (Eg) for direct and indirect transitions "absorbance, refractive index,  extinction coefficient, real and imaginary parts" of the dielectric constant.


Author(s):  
J. Damisa ◽  
J. O. Emegha ◽  
I. L. Ikhioya

Lead tin sulphide (Pb-Sn-S) thin films (TFs) were deposited on fluorine-doped tin oxide (FTO) substrates via the electrochemical deposition process using lead (II) nitrate [Pb(NO3)2], tin (II) chloride dehydrate [SnCl2.2H2O] and thiacetamide [C2H5NS] precursors as sources of lead (Pb), tin (Sn) and sulphur (S). The solution of all the compounds was harmonized with a stirrer (magnetic) at 300k. In this study, we reported on the improvements in the properties (structural and optical) of Pb-Sn-S TFs by varying the deposition time. We observed from X-ray diffractometer (XRD) that the prepared material is polycrystalline in nature. UV-Vis measurements were done for the optical characterizations and the band gap values were seen to be increasing from 1.52 to 1.54 eV with deposition time. In addition to this, the absorption coefficient and refractive index were also estimated and discussed.


2011 ◽  
Vol 8 (2) ◽  
pp. 561-565
Author(s):  
Baghdad Science Journal

Cr2O3 thin films have been prepared by spray pyrolysis on a glass substrate. Absorbance and transmittance spectra were recorded in the wavelength range (300-900) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity were expected. It was found that all these parameters increase as the annealing temperature increased to 550°C.


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