Recent advances in soft optical glass fiber and fiber lasers

The goal of this study was to investigate the structure and optical properties of the prepared PVC/NiO nanocomposites. The samples were characterized via XRD, TEM, SEM, and UV–Vis spectrophotometer experimental measurements. The partial crystal structure of PVC/NiO nanocomposites and cubic structure of NiO nanoparticles were explored by X-ray diffraction. SEM exhibited the good distribution of the nanoparticles in PVC films. Linear optical parameters: refractive index and normalized absorption, increased whenever transmission and reflection reduced by adding NiO nanoparticles. Direct and indirect optical band gaps were obtained from Tauc’s formula, and it was found that both direct and indirect optical band gaps decrease as more NiO nanoparticles added. The direct optical band gap decreases from 5.20 to 5.15 eV. The optical conductivity increased by increasing the content of NiO nanoparticles. The dispersion parameters: oscillator energy $$E_{0}$$
 , dispersion energy $$E_{\text{d}}$$
 , plasma angular frequency $$w_{\text{p}}$$
 , optical momentum of dispersion $$M_{ - 1}$$
 and $$M_{ - 3}$$
 , and static refractive index, were calculated by using Wemple and DiDominco model. The nonlinear optical susceptibility $$x^{(3)}$$
 and nonlinear refractive index $$n_{2}$$
 were evaluated from the linear optical parameters using semiempirical relation. The increasing in nonlinear parameters $$x^{(3)}$$
 and $$n_{2}$$
 suggest the use of PVC/NiO nanocomposites for nonlinear optical applications.

Effect of NiO NPs doping on the structure and optical properties of PVC polymer films

Chalcogenides-based quantum dots: Optical investigation using first-principles calculations

The current research aims to synthesize and investigate the optical spectroscopy of PVA/iron polymer nanocomposites. The polymer films prepared via dissolving powders and characterized by XRD, SEM and optical spectroscopy measurements. The analysis of XRD depicted the cubic crystal structure of γ-Fe2O3 nanoparticles with average crystallite size 42.40 nm. SEM monographs provided the complete interaction between γ-Fe2O3 and PVA polymer matrix. Optical absorption measurements of the PVA/iron oxide polymer nanocomposites displayed a red shift of the absorption edge with the iron oxide content. The optical indirect energy gaps estimated from optical absorption data decreased from 5.0 to 2.4 eV with the iron oxide content. In addition, the refractive index values enhanced with the concentration of iron oxide. Comparing the energy gap values estimated from Tauc's formula and optical dielectric loss function confirmed the major electronic transitions as direct allowed. The fluorescence spectra of the PVA/iron polymer nanocomposites displayed emission peaks centered at 421, 451 and 469 nm and the intensity reduced with the ratio of iron oxide.

Micro-structure and optical spectroscopy of PVA/iron oxide polymer nanocomposites

In this contribution, MnO2 doped borate glass matrix with ratios 0.0, 0.5, 1.0, 1.5 and 2.0 wt% were prepared utilizing melting method. The structural characterization of these glass samples was performed via X- ray diffraction measurements. Optical absorption analyses within the 200–1000 nm wavelength range were performed to characterize the samples. The direct and indirect optical energy gaps (Eopt) decreased however Urbach energy (EU) increased with increasing MnO2 concentration. The refractive index, and optical conductivity values are observed to increase with increasing MnO2 concentration. FTIR spectra of borate glass doped with 0.0, 0.5, 1.0, 1.5 and 2.0 wt% MnO2 revealed the presence of absorption bands due to Mn2+.

Preparation and optical properties of borate glass doped with MnO 2

Novel PbSe nanocrystals doped fluorogermanate glass matrix

Characterization and growth of lead telluride quantum dots doped novel fluorogermanate glass matrix

Cadmium sulfide nanoparticles were grown in Na2O–GeO2 glass matrix by a diffusion-controlled phase decomposition of over-saturated solid solution. The structural properties of CdS nanocrystals have been studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), optical absorption and electrical conductivity. The existence of CdS nanocrystals was confirmed by XRD and TEM, also its crystallite sizes are obtained. The average CdS crystallite sizes calculated from XRD analysis for the different heat-treatment conditions are found in the range between 23.7 and 48.8 nm; however, the average CdS crystallite sizes obtained from TEM micrographs are found in the range between 17 and 63 nm. The band gap energy Eopt and the activation energy Eg for the electrical conductivity have been increased with decrease in the particle size; however, the Urbach energy ΔE decreases with decreasing the nanocrystal size.

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T.A. Taha

Papers

Novel PbSe nanocrystals doped fluorogermanate glass matrix

Characterization and growth of lead telluride quantum dots doped novel fluorogermanate glass matrix

Synthesis and characterization of CdS nanocrystals embedded in germanate glasses