Linear Refractive Index Research Articles

Design of an all-optical tunable 2D photonic crystal in As2S3 film

Amorphous arsenic trisulphide (As2S3) chalcogenide glass is widely used in photonics and optoelectronics due to its wide transparency in the infrared spectral range, its high linear refractive index (nAs2S3 = 2.42), which can be significantly modified by light with a suitable wavelength, and its important optical nonlinearity. In this work, we report the design of an all-optical tunable two-dimensional photonic crystal in a geometry which consists in a hexagonal lattice of holes patterned in As2S3 film with the aim to exhibit photonic band gap in the near infrared domain. We numerically investigated the possibility to all-optically tune the photonic band gap of an already patterned photonic crystal in As2S3 modifying only its refractive index by illumination with light of wavelength λ at the band gap energy (λ = 514.5 nm) or shorter, without affecting the lattice geometry. The influence of the variation of As2S3 refractive index (Δn) on the spectral position of the band gap and on its width has been determined for the light-induced modification of Δn up to the value of 0.09. For this value of Δn, a shift of almost 50 nm of the central wavelength of the photonic band gap has been obtained. These results are of great interest in the field of photonics offering a versatile solution to fabricate all-optical tunable photonic crystals in any optical material whose refractive index can be modified by light.

Nonlinear optical parameters and electronic properties of plasma polymerized methyl acrylate thin films

Plasma polymerized methyl acrylate (PPMA) thin films were fabricated on a borosilicate glass substrate at a plasma power of 28 W to study nonlinear optical parameters and electronic properties. X-ray Diffraction analysis confirmed the amorphous nature of the PPMA films, while Attenuated total reflectance Fourier transform infrared spectroscopy indicated monomer fragmentation due to plasma polymerization. Field emission scanning electron microscope images of the films display a water wave-like structure. PPMA films demonstrated thermal stability up to approximately 574 K in both N2 and air environments. The values of direct band gap energies increase from 3.30 to 3.41 eV with increasing film thicknesses, whereas the Urbach energy values show in an opposite manner. The Wemple-DiDomenico model was employed to analyze both the oscillator energies ranging from 5.54 to 6.44 eV and the dispersion energies ranging from 10.56 to 12.89 eV. The static linear refractive index showed typical dispersion behavior, with film thickness conforming to Moss's rule. The nonlinear refractive index and 2nd and 3rd order nonlinear susceptibilities decrease with increasing the studied films. The lattice dielectric constant values exceeded the high-frequency dielectric constant, indicating the presence of lattice vibrations and free carriers. Electronic parameters are fluctuating with increasing film thickness. The observed changes in nonlinear optical parameters and electronic properties highlight the potential of PPMA films for applications in photovoltaic and optoelectronics.

Influence of d-d transition electrons and thickness variations on the excited-state optical properties: Nonlinear optical characterization of Cr2O3 thin film

The structural, morphological, linear, and nonlinear optical properties of Cr2O3 thin films with different thicknesses deposited by the thermal deposition, were measured. The structural and morphological parameters of films, determined by XRD, FESEM, and AFM images, are compared to the linear and nonlinear optical characteristics of these media. The bandgap of prepared thin films was obtained from DRS spectra. The electron effective mass (me∗/m0), linear refractive index (n0), optical static, and high frequency dielectric constant (ε0 , ε∞) values were calculated by using the band gap energy values. Increasing the thicknesses of thin films causes to decrease the band gap, an increase RMS, increase the size of nanoparticles and the nonlinear responses of thin films. The high magnitude of n2, and β belonged to the Cr2O3 (300 nm-thickness) in the order of 10−5 cm2/W, and 10−1 cm/W respectively. The fluctuations in nonlinear responses observed at different thicknesses are attributed to d-d transitions and intraband scattering of equilibrium electrons influenced by laser radiation, as indicated by the nonlinearity data. The considerably elevated refractive non-linearity values in the analyzed film materials suggest their potential for practical applications in optoelectronic devices.

(Cd)SO4 doping on L-Valine crystal for the enhancement of opto-electronic and laser properties

L-Valine is a good molecular platform to induce NLO properties for Laser application and considerable laser properties can be improved by injecting suitable electron administrated substitutional groups. This work is an attempt to make laser properties enhancement by increasing Cd solvent concentration on L-Valine compound. The recorded XRD peaks addressed the significant increment of laser properties of the composite crystal. The results obtained for pure L-Valine was; a=5.221 (Å), b=6.910 (Å) and c=4.994 (Å) and associated indices of refraction was n1=1.511, n2=1.583 and n3=1.599. The results of 2% CdSO4; a=5.580 (Å), b=7.011 (Å) and c=5.091 (Å) and associated indices of refraction was n1=1.561, n2=1.612 and n3=1.633. For 5% CdSO4; a=5.599 (Å), b=7.831 (Å) and c=5.659 (Å) and associated indices of refraction was n1=1.588, n2=1.661 and n3=1.699. For 10 % CdSO4; a=5.592 (Å), b=7.612 (Å) and c=5.822 (Å) and associated indices of refraction was n1=1.661, n2=1.693 and n3=1.593. For 15 % CdSO4; a=5.551 (Å), b=6.332 (Å) and c=4.734 (Å) and associated indices of refraction was n1=1.501, n2=1.599 and n3=1.593. The non linear refractive index was changed from 3.891 X 10-8 cm2/W to 4.231 X 10-8 cm2/W for 2%, 5%, 10% respectively and Third order non linear optical susceptibility (χ(3)) was ranged from 4.621X10‑6 esu to 5.091X10‑6 esu. The restored chemical potential for non linear optical (NLO) and birefringence properties was found to be improved. The scattering capability of homo nuclear and hetero nuclear bonds along with the CdSO4 voids was identified for attaining non linear scattering process.

Study of radiation-induced structural changes in the near-surface layer of ZrO2 ceramics caused by He2+ irradiation

Abstract The aim of this study is to determine changes in the near-surface layer of ZrO2 ceramics caused by irradiation with low-energy He2+ ions, as well as the associated formation of defects and structural deformations. During the experimental work conducted, it was established that the accumulation of deformation-structural distortions is of two stage nature, having a direct dependence on irradiation fluence and, therefore, on atomic displacement value. It was determined that at small atomic displacement values (less than 10 dpa), the main mechanisms of structural distortions are caused by tensile residual stresses, the value of which is less than 0.1 GPa. At the same time, the deformation distortion of chemical bonds has a pronounced anisotropy associated with a more pronounced distortion of the Zr–OI chemical bonds, the distortion of which results in the formation of vacancy defects in the form of VO. During determination of alterations in optical characteristics depending on the atomic displacement value, it was found that the dominant role at small values of dpa (less than 10 dpa) is played by point defects, which influence the formation of obstacles in the form of absorbing centers. In this case, an increase in the irradiation fluence above 1017 ion/cm2 results in a growth in the linear refractive index, the change of which has a direct correlation with the value of residual stresses in the damaged layer. Certain dependencies of changes in structural features and their relationship with deformation distortions, as well as the accumulation of vacancy defects, can subsequently be used to predict the potential of using these ceramics as materials for new generation nuclear reactors.

Cerium oxide-reinforced Fe2O3–Na2O–SiO2–B2O3 glass matrix for protection against ionizing X and gamma rays

Radiation shielding glass is an interesting material in the field of radiation shielding due to its remarkable features. In the present paper, we investigated the physical properties of radiation-shielding glass materials that consist of sodium oxide (Na2O), cerium oxide (CeO2), and iron oxide (Fe2O3) incorporated into borosilicate glasses with the formula 90SiO2-(70-x)B2O3+ 20Na2O–1Fe2O3-xCeO2 (CeFeNaBS-glasses). One of the distinguishing characteristics of this glass system is its enhanced radiation shielding capabilities. The structural studies indicated a gradual rise in glass density from 1.954 to 2.658 g/cm with further CeO2 doping. Optical studies showed that the optical band gaps went down from 3.41 eV to 3.33 eV as the amount of CeO2 in the CeFeNaBS-glass matrix rose. The decrease in optical band gap has been correlated with the rising basicity. Also, the increased basicity behavior induces more conversion of Ce3+ to Ce4+ ions by losing a 4f electron. Moreover, with further CeO2 additions, the glass color changed from light brown to dark brown. The presence of Ce4+ ions with further CeO2 additions is responsible for this color transformation. The linear and non-linear refractive indices exhibit enhanced behaviors with higher CeO2 concentrations. We used declining basicity and polarizability behaviors to describe this behavior. The incorporation of larger CeO2 concentrations enhances the ability to improve radiation shielding properties, as demonstrated by the increased values of the mass attenuation coefficient and half-value layer, especially in the energy ranges of soft tissues X-ray and hard tissues X-ray. Hence, the investigated CeFeNaBS-glasses exhibit enhanced transparency and radiation shielding capabilities, rendering them highly suitable for implementation in this domain.

Influence of La3+ ions on the structural, elastic, optical, and radiation shielding properties of Cr2O3-Doped heavy metal glasses

This study investigates the effect of La³⁺ rare earth ions on the structural, elastic, optical, and radiation shielding features of heavy metal borate glass (B₂O₃-PbO) doped with Cr₂O₃. Density measurements and FT-IR spectra analysis revealed the role of La3+ ions as a network modifier, where successive additions of La2O3 content led to a gradual increase in the density and an increase in the non-bridging oxygen content resulting from the structural transformation between the BO4 and BO3 units. The significant improvement in the elastic modulus and microhardness factor moduli was confirmed by calculating the change in ultrasonic velocities through the glassy system. The structural modifications induced by La³⁺ ions narrowed the band gap and increased the Urbach energy, indicating higher disorder within the glass network. The linear refractive indices increased due to increased optical basicity and electronic polarization. Optical absorption results showed that Cr⁶⁺/Cr³⁺ ions occupy octahedral/tetrahedral sites, with the tendency for Cr³⁺ cations to occupy more octahedral sites with increasing La₂O₃ content. The produced samples showed a greenish-yellow color caused by the absorption band centered at ∼415 nm associated with the electronic transition ⁴A₂g(F)→2Eg(G). The ligand field effect highlighted the significance of La³⁺ cations in increasing the crystalline field intensity surrounding Cr³⁺ cations and reducing the nephelauxetic ratio, signifying enhanced covalent character between Cr³⁺ cations and neighboring ions. Moreover, the radiation shielding capabilities of the glassy system were analyzed and compared with standard shielding materials, confirming superior shielding performance in samples with the highest La₂O₃ content.

Exploring the effect of thin film thicknesses on linear and nonlinear optical properties of MoO3 thin film

The structural, morphological, linear, and nonlinear optical properties of MoO3 thin films deposited by thermal deposition were measured. The effect of various thicknesses of films was studied. The structural and morphological parameters of films, determined by x-ray diffraction, field emission scanning electron microscopy, and AFM images, are compared to the linear and nonlinear optical characteristics of these media. The bandgap of the prepared thin films was obtained from the diffuse reflectance spectroscopy spectra. The electron’s effective mass (me*/m0), linear refractive index (n0), and optical static and high frequency dielectric constant (ɛ0, ɛ∞) values were calculated by using the bandgap energy values. Increasing the thicknesses of thin films decreased the bandgap, increased the root mean square, and increased the size of nanoparticles and the nonlinear response of thin films. The high magnitude of n2 and β was because of MoO3 (300 nm-thickness), which were of the order of 10−5 cm2/W and 10−1 cm/W, respectively. The fluctuations in nonlinear responses observed at different thicknesses are attributed to d–d transitions and intraband scattering of equilibrium electrons influenced by laser radiation, as indicated by the nonlinearity data. The considerably elevated refractive nonlinearity values in the analyzed film materials suggest their potential for practical application in optoelectronic devices.

Designing an imaging spectrometer with high resolution using manufacturable gradient-index (MGRIN) lenses with a linear distribution of refractive index.

In this work, an imaging spectrometer with a diffraction-limited resolution of 0.043nm is designed by using two manufacturable gradient-index (MGRIN) lenses with a linear refractive index distribution to suppress the aberrations. The MGRIN lenses are made from a combination of two separate base materials that their refractive indices are determined by the fractional composition of each base material at any point. The volume fraction of each base material in both lenses changes linearly from the front edge to the rear vertex of the lens. The input light to the spectrometer originates from a single-mode fiber with a core diameter of 9μm and a numerical aperture of 0.1. The parallel rays after passing through the collimator are diffracted by a diffraction grating with a number of grooves of 1200 g/mm. The criteria determining the quality of the image show that the aberrations of the image have been optimally controlled. Comparing the results of this design with some similar studies done by other researchers shows that the root-mean-square radius of the spot diagram and Airy disk radius are significantly smaller than those designs. In addition, the modulation transfer function diagram has a better fit with the diffraction limit curve. These results make our proposed spectrometer have a stronger resolution than those in previous studies.

Exploring the nonlinear optical properties of hypoxanthinium salts: a structural and computational analysis.

In this study, we detail the synthesis and crystallographic characterization of an unprecedented structure, specifically hypoxanthinium chloride monohydrate ((I) hereafter), which crystallizes in the monoclinic P21/c space group. A comparative analysis was conducted with four related hypoxanthinium salts: hypoxanthinium bromide monohydrate (II), 9-methylhypoxanthinium chloride monohydrate (III), hypoxanthinium nitrate monohydrate (IV), and hypoxanthinium perchlorate monohydrate (V). This analysis has focused mainly on their crystal packing, hydrogen-bonding networks, and non-classical intermolecular interactions, as elucidated by comprehensive Hirshfeld surface and topological analyses. Theoretical investigation of the nonlinear optical (NLO) properties of the hypoxanthinium derivatives (I-V) was performed using the Density Functional Theory (DFT). The crystalline environment was simulated using the iterative Supermolecule method (SM), and the static and dynamics linear refractive index, linear polarizability, second-order hyperpolarizability, and the third-order nonlinear susceptibility at the DFT/CAM-B3LYP/6-311++G(d,p) level were computed. The results for the macroscopic third-order nonlinear susceptibility of (II) was found to equal . By replacing the bromine atom in (II) with a chlorine atom as in (III), the value will be multiplied by 2.16, and therefore these results are large enough to suggest the potential application of these crystals as NLO materials.

Electric field-induced modulation of electronic and optical properties in doped CdTe/CdS core/shell quantum dots embedded in an oxide matrix

This work presents a theoretical analysis of a CdTe/CdS core/shell quantum dots embedded in a dielectric oxide matrix under the influence of hydrogenic impurity and the applied electric field intensity. The eigenstates and their corresponding eigenfunctions are computed by solving the Schrodinger equation using the finite element method within the effective mass approximation. The first-order linear and third-order nonlinear optical absorption coefficients as well as the refractive index changes are computed based on the compact density matrix approach. The obtained result shows that the first-order linear and third-order nonlinear optical properties are more pronounced with the electric field, surrounding oxide matrix and the donor impurity effects. However, the first-order linear and third-order nonlinear optical absorption coefficients and refractive index changes can experience a red or blue shift under the influence of electric field, oxide matrix and hydrogenic impurity. In addition, under all conditions, the height peaks of these optical properties can be raised (fall). Our findings demonstrate the critical importance of considering the roles of electric field, the presence of donor impurity, and the capped dielectric oxide matrix in the design and fabrication of core–shell-based optoelectronic devices.

The effect of hydrostatic pressure, temperature and impurity factor on linear and nonlinear optical properties of InxGa1-xAs tuned quantum dot with modified Gaussian potential under the action of a vertical magnetic field

This study presents a detailed theoretical analysis of the effects of hydrostatic pressure, temperature, impurity factors, and external electric fields on the optical properties of InxGa1-xAs tuned quantum dot. A uniform magnetic field, directed perpendicular to the quantum dot plane, is applied. The system is excited using a monochromatic electromagnetic field, considering electron intersubband transitions. Energy levels and wave functions are determined using the parabolic band approximation and effective mass approximation. The linear and nonlinear optical absorption coefficients and refractive index changes are computed using the compact-density matrix approach and the iterative method. Numerical results indicate that the peaks of the linear and nonlinear optical absorption coefficients and refractive index changes shift towards lower energies (red shift) and higher energies (blue shift) under varying hydrostatic pressure, temperature, and impurity factor strength. Additionally, the peak values of the absorption coefficients and refractive index changes increase or decrease based on these parameter variations. These results have significant implications for the design and optimization of quantum dot-based optoelectronic devices.

Styrene monomer as potential material for design of new optoelectronic and nonlinear optical polymers: density functional theory study.

Using density functional theory, we have studied the intrinsic properties of styrene. First, we determine the optimized structures, structural parameters and thermodynamic properties to make our simulations more realistic to experimental results and check the stability. Second, we investigate optoelectronic, electronic and global descriptors, transport properties of holes and electrons, natural bond orbital analysis, absorption and fluorescence properties. Finally, we study nonlinear optical (NLO) properties: first- and second-order hyperpolarizability, second and third-order optical susceptibilities, hyper-Rayleigh scattering hyperpolarizability, electro-optical Pockel effect, direct current Kerr effects and quadratic refractive index. The bandgap energy E g = 5.146 eV and dielectric constant show that styrene is a good insulator with an average electric field value of 4.43 × 108 Vm-1. Thermodynamic findings show that our molecule is thermodynamically and chemically stable. Electron and hole reorganization energies of 0.393 and 0.295 eV, respectively, show that styrene is more favourable to hole transport than electron transport. Styrene is transparent with linear refractive index n = 1.750 and quadratic n 2 = 1.748 × 10-20 m2 W-1. At the NLO, styrene has a non-zero value of which confirms the existence of first-order NLO activity. Globally the study shows that the styrene monomer is suitable for the architecture design of new polymer materials for NLO applications and optoelectronic by functionalization.

The effect of the noise on the dynamics of soliton generation in microresonator

The study demonstrated that noise changes the number of modes that can oscillate within the small cavity, and the spectral power is concentrated around the fundamental frequency. We also observed a reduction in the distortion that arises from the dispersive solitaire. This behaviour can be attributed to the magnitude of the pulse strength or the loss of its frequency due to the arbitrary interaction between the pulse train and the linear and nonlinear refractive index of the microcavity. The relationship between the dispersion and nonlinearity phenomena inside the microresonators is major in determining the inside field dynamics. The study showed that as the noise in microresonators cannot be cancelled, it is recommended to use a proper pulse width, intensity distribution, and power.

B2O3+SiO2+BaO+Sm2O3+Na2O+MoO3 glasses: Preparation, optical, physical characteristics as well as γ-ray absorption ability

Samples of borosilicate glasses reinforced with various moles of MoO3 with general chemical formula (52-X)B2O3+13SiO2+19.75BaO+ 0.25Sm2O3+15Na2O+XMoO3: (0.0 (BSMO-0.0) ≤ X ≤ 10.0 (BSMO-10.0) mol%) were prepared using the melt-quenching technique. The physical, optical absorption, electronic transitions, and linear/nonlinear optical properties as well as γ-ray absorption capacity has been investigated. Density (ρ) of the BSMO-X glasses enhanced from 2.83 g cm−3 to 3.16 g cm−3. Molar volume (Vm) gradually decreased from 29.81 cm3/mol to 29.10 cm3/mol as MoO3 concentration increased from 0.0 to 10.0 mol% in the glass network. The BSMO-X glass samples exhibit absorption peaks at wavelengths of 402, 476, 936, 1072, 1227, 1368, 1469, 1527, and 1944 nm which associated with the electronic transitions originating from the lowest energy state (6H5/2) to 6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6H13/2 states, respectively. The indirect optical energy gap (Eg) changed from 3.15 eV to 2.82 eV, while the linear refractive index (no) increased from 2.37 to 2.44. Mass- (MAC) and linear- (LAC) absorption coefficients increased as MoO3content increased in the glass network. The BSMO-10.0 possessed the lowest values of half-value (HVL) layer among all investigated samples. The BSMO-X glasses achieve higher capability in radiation shielding than some standard concrete and glasses.

Tuning the structural, optical and dielectric features of PMMA/PEO/PANi blend using nano MnFe2O4

This study aimed to incorporate MnFe2O4 nanoparticles into a nanocomposite blend of poly (methyl methacrylate, PMMA), polyethylene oxide (PEO), and polyaniline (PANi). The incorporation was achieved using straightforward, environmentally friendly, and cost-effective techniques. The structures of MnFe2O4 and PMMA/PEO/PANi/x wt % MnFe2O4 were examined using X-ray diffraction (XRD) and/or transmission electron microscopy (TEM) techniques. The diffused reflectance technique was employed to investigate the linear optical properties of all blends, including absorbance, transmittance, reflectance, extinction coefficient, linear refractive index, optical dielectric constant and optical conductivity. PMMA/PEO/PANi blend has direct and indirect energy gaps of 5.33 and 4.65 eV, respectively. As MnFe2O4 doping level increased to 2.5 wt%, the smallest direct and indirect energy gap values of 5.16 and 4.08 eV were obtained, respectively. The addition of 1 wt% MnFe2O4 to the blend increased the refractive index value at 600 nm to 2.24. Nonlinear optical parameters of PMMA/PEO/PANi/x wt% MnFe2O4 blends were calculated. The emitted colors and their purities of all blends were investigated as a function of MnFe2O4 concentration. The obtained results suggested that the PMMA/PEO/PANi/x wt% MnFe2O4 blends may be used in a variety of optoelectronic and storage applications.

Influence of pH on growth, structural, thermal, linear and nonlinear optical properties of L-asparagine monohydrate single crystal

This report presents investigation on influence of pH on growth, structural, thermal, linear and nonlinear optical properties of L-asparagine monohydrate (LAM) single crystal for the first time. Single crystals of LAM were grown at different pH by solution growth method by allowing slow evaporation of solvent. Crystal grown at pH 6.4 grows slowly as compare to other crystals grown at other pH values. The slight variation in lattice parameters of grown crystals has been confirmed by powder X-ray diffraction study. FT-IR study confirms the presence of functional groups of LAM in all grown crystals. Influence of pH on optical quality of crystals has been discussed. The crystal grown at pH 5.4 has maximum optical transparency and shows 2 and 20 % more transmission than crystals grown at pH 4.4 and 6.4, respectively. Other optical parameters like cutoff wavelength (λmax), band gap (Eg), linear refractive index (n), reflectance, extinction coefficient (k), electrical susceptibility (χ), optical conductivity(σop), electrical conductivity (σel) and Urbach energy (Eu) of all crystals have been evaluated from transmission data. The LAM crystal grown at pH 6.4 show high values of third order nonlinear optical parameters, as compare to other grown crystals, that attest its suitability for applications like higher harmonic generation, optical switching, optical limiting and other photonic applications over other grown crystals. Thermal stability of the grown crystals has been attested by TG-DTA study.

Unveiling the enhanced optical limiting of polyaniline – Fullerene composite investigated by z-scan

The reverse saturable absorption (RSA) and optical limiting (OL) mechanisms of polyaniline (PANI) and fullerene doped PANI (PANI-C60) solutions were investigated by open-aperture z-scan studies, using a nanosecond pulsed Nd:YAG laser operating at 532 nm wavelength as the excitation source. The nonlinear absorption coefficient (β), OL threshold, and imaginary part of nonlinear susceptibility (χi(3)) of PANI and PANI-C60 solutions were determined for three different laser input pulse energies and are found to be in the order of 10−9 cm/W, 106 W/cm2, and 10−10 esu respectively. The results showed enhanced OL efficiency for the PANI-C60 solution, making it a promising candidate for applications in optoelectronics and optical limiting. The transmission electron microscope (TEM) images revealed the uniform distribution of C60 of particle size in the range of 5–10 nm in the PANI matrix. The composite formation of PANI-C60 was confirmed by Fourier transform infrared spectroscopy (FTIR). The presence of C60 and its charge transfer complex (CTC) formation with PANI are responsible for the enhanced OL efficiency. The linear refractive index values were measured using UV–Visible absorption spectra and compared with the theoretical values. The investigation of the OL mechanism and the calculation of its associated NLO parameters for PANI and PANI-C60 solutions are reported for the first time.

Investigation of borate glasses reinforced with iron (III) oxide [Fe2O3]: Preparation, physical, UV–Vis properties and γ-ray attenuation efficacy

Five samples of borate glasses reinforced with various ratios of Fe3+ ions with chemical formula (60-X)B2O3–10ZnO–10CdO–5Li2O–15Na2O-XFe2O3: (0.0 (Fe-0.0) ≤ X ≤ 1 (Fe-1.0) mol%) were prepared using the melt-quenching technique. The structure, physical, optical characteristics, and γ-ray attenuation properties of the prepared Fe-X glasses have been investigated. The amorphous state of Fe-X glasses confirmed by XRD observations. Density (ρglass) of the Fe-X glasses increased from 3.21 g cm−3 to 3.91 g cm−3. Molar volume (Vm) gradually reduced from 18.87 cm3/mol to 15.35 cm3/mol with increasing Fe2O3 content in the glass network from 0.0 to 1.0 mol%. The color of Fe-X glasses changed from yellow to brown according to the absorption bands located at around 385–412 nm and 407–429 nm within the visible spectrum. The indirect optical band gap (Eg) decreased from 3.37 eV to 2.78 eV, while the linear refractive index (no) increased from 2.31 to 2.45. Mass- (MAC) and linear- (LAC) attenuation coefficients increased as Fe3+ ions increased in the glass network. The Fe-1.0 sample with highest Fe2O3 content possessed the lowest values of half-value layer (HVL) and mean free path (MFP) shielding parameters. Results revealed that the suggested glass compositions can be applied in optical and radiation protection fields.

Tailoring the optical performance of sprayed NiO nanostructured films through cobalt doping for optoelectronic device applications

The current study aims to tailor the structural and nonlinear/linear optical characteristics of NiO nanostructures for optoelectronic applications. The spray pyrolysis procedure was applied to synthesize Ni1-xCoxO nanostructured films (x; 0, 0.04, 0.08, 0.12, 0.16 and 0.20). The functional groups and morphological investigation were performed by the FT-IR and SEM techniques. The structural and optical properties were investigated based on XRD and UV–vis measurements. The XRD investigations reveal that all samples have a cubic crystalline structure. The UV–vis analysis shows that the optical absorption of NiO nanostructures increased, and the energy bandgap decreased from 3.85 eV to 3.40 eV through cobalt doping. The Herve-Vandamme model was applied to investigate the linear refractive index for all samples. The nonlinear optical (NLO) behavior of all samples has been investigated. A significant improvement was accomplished through cobalt doping in the linear refractive index, optical conductivity, dielectric constants, NLO susceptibility and NLO refractive index of NiO. The achieved results suggest that cobalt-doped NiO nanostructured films have potential applications in linear/nonlinear optical devices and data storage.