scholarly journals Improved absorbance of holmium activated magnesium-zinc-sulfophosphate glass

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Siti Aishah Jupri ◽  
Sib Krishna Ghoshal ◽  
Muhammad Firdaus Omar ◽  
Sunita Sharma
Keyword(s):  
Refractive Index ◽  
Optical Absorption ◽  
Glass Network ◽  
Band Gap Energy ◽  
Photonic Devices ◽  
Rare Earth Ions ◽  
Glass System ◽  
Absorption Properties ◽  
Small Component ◽  
Light Amplifier

Constant efforts are dedicated to overcome the limitations of phosphate based glass system, where sulfophosphate glasses (SPGs) played a key role. Rare earth ions (REIs) doped magnesium zinc SPG (MZSPG) systems are technologically prospective due to their several unique attributes. Construction of integrated light amplifier and solid state laser needs the maximum gain within small component dimensions. Thus, Ho3+ ions doped SPGs are believed to meet this demand. Ho3+ ions having sharp optical absorption peaks in the spectral range of 200–900 nm is useful for diversified applications. Conversely, SPGs comprising of oxides of sulphur, phosphorous and at least one other component with SO42- ions contents lower than PO43- with low melting temperature makes them a distinctive class of technologically potential disordered system. In this view, modification of Ho3+ ions absorbance inside SPGs network is challenging. To achieve this goal, following melt-quenching route we prepared a series of Ho3+-doped MZSPG system of composition (60-x)P2O5-(20)ZnSO4-(20)MgO–(x)Ho2O3, where x = 0.0, 0.5, 1.0, 1.5 2.0, and 2.5 mol%. The influence of Ho2O3 concentration on the density, refractive index, and optical absorption properties of the synthesized glass system is examined. The density and refractive index is found to increase with increasing Ho2O3 concentration. The absorption spectra revealed nine prominent peaks centered at 387, 418, 450, 484, 538, 642, 1148 and 1945 nm. The glass absorbance is enhanced with increasing Ho3+ contents. Optical band gap energy is found to range from 3.847 to 3.901 eV. The reduction of Urbach energy from 0.257 to 0.191 eV with increasing Ho3+ contents verified the shrinkage of glass network structure and lowering of defect mediated disorder. In-depth investigations on the structural and optical properties of MZSPG system are underway to achieve the milestones set for photonic devices.

scholarly journals Modified absorption attributes of neodymium doped magnesium-zinc-sulfophosphate glass

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Nur Nabihah Yusof ◽  
Sib Krishna Ghoshal ◽  
Muhammad Firdaus Omar
Keyword(s):  
Rare Earth ◽  
Glass Network ◽  
Xrd Analysis ◽  
Photonic Devices ◽  
Rare Earth Ions ◽  
Glass System ◽  
Ion Concentration ◽  
Subsequent Transformation ◽  
Physical Density ◽  
Doped Glass

Rare-earth doped glass systems with improved absorption and emission features are greatly demanding for diverse applications. In this endavour, selection of right glass host, modifier, rare earth ions with optimized composition is the key issue. This communication reports the conventional melt-quench synthesis of neodymium (Nd3+) doped magnesium-zinc- sulfophosphate glass system of the form (60-x)P2O5-20MgO-20ZnSO4-xNd2O3 (x = 0, 0.5, 1, 1.5, 2.0 and 2.5 mol%). The influence of varying Nd3+ contents on the physical (density, molar volume, molar refractivity, refractive index and electronic polarizability) and absorption properties of the prepared glass system is determined. The amorphousity of the obtained samples is confirmed by XRD analysis. The glass refractive indices (ranged from 1.85 to 1.90)  and densites (between 2.63 to 2.77 g.cm-3) are found to increase with increasing concentration of Nd3+ ion. Furthermore, the energies associated with the direct and indirect optical transitions across the forbidden gap are observed to reduce with the increase of Nd3+ ion concentration. Meanwhile, the increase of Urbach energy with increasing Nd3+doping is ascribed to the interaction of rare earth ions with the ligands of the glass network and subsequent transformation of weak bonds into defects. The room temperature UV–Vis-NIR spectra revealed eleven absorption band corresponding to the transitions from the ground state to various excited states of the Nd3+ ion. Incorporation of  Nd3+ ion is discerned to enhance the glass absorbance appreciably together with the alteration of physical properties. Present findings may be beneficial for the advancement of Nd3+ ions doped magnesium-zinc-sulfophosphate glass system based photonic devices especially for infrared solid state laser.

Absorption and Raman Spectra of Dy3+ Doped Tellurite Glass: Combined Effects of Silver and Titanium Nanoparticles

2017 ◽  
Vol 268 ◽  
pp. 111-116
Author(s):  
Mohd Syamsul Affendy bin Mohd Saidi ◽  
Sib Krishna Ghoshal ◽  
Ramli Arifin ◽  
Mohamad Khairil bin Roslan
Keyword(s):  
Electric Field ◽  
Raman Spectra ◽  
Tellurite Glass ◽  
Rare Earth Ions ◽  
Glass System ◽  
Noble Metal Nanoparticles ◽  
Spectroscopic Techniques ◽  
Combined Effects ◽  
Absorption Bands ◽  
Absorption Properties

Obtaining enhanced up-conversion efficiency in rare earth ions doped inorganic glass by means of noble metal nanoparticles (NPs) embedment remains challenging. For the first time, we report the combined effects of silver (Ag) and titania (TiO2) NPs embedment on the structural and absorption characteristics of dysprosium (Dy3+) doped tellurite glass. Transparent and thermally stable glass samples were prepared using conventional melt quenching method and characterized via spectroscopic techniques. The production of the strong electric field in the proximity of Dy3+ ion due to the localized surface plasmon (LSP) of embedded metallic NPs was found to improve the glass absorption properties. The effects of bimetallic NPs in changing the structure and absorption properties were found to be better than singly included metallic NP (either Ag or TiO2). This improvement in the absorption behavior was attributed to the combined LSP resonance (LSPR) effects of Ag and TiO2 NPs which transferred strong local electric field into the Dy3+ ions positioned in their vicinity. The UV-Vis-NIR spectra revealed six absorption bands centerted at 1690, 1283, 1097, 904, 800 and 755 nm which were allocated to the transition from 6H15/2 ground state to various excited states (6H11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2 and 6F3/2) of Dy3+ ion. Furthermore, the Raman spectra of such bimetallic NPs included glass system exhibited Raman peak shift accompanied by intensity variations when compared to the glass system with only one type of NPs incorporation. This enhancement in the Raman signal was ascribed to the LSPR mediated mechansim. The synthesized glass comporition was asserted to be prospective for devices.

Optical Properties of Eu3+-Doped Lithium Tellurite Glass

2015 ◽  
Vol 1107 ◽  
pp. 432-436 ◽  
Author(s):  
Siti Aishah Jupri ◽  
Md Rahim Sahar ◽  
Sib Krishna Ghoshal
Keyword(s):  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Glass Network ◽  
Band Gap Energy ◽  
Melt Quenching ◽  
Absorption Properties ◽  
Gap Energy ◽  
Controlled Doping

Improving the optical response of tellurite glasses via controlled doping of rare earth is the key issue in lasing materials. A series of glasses of the form (74.4-x)TeO2(4.3)Li2O(21.3)LiCl (x)Eu2O3 with 0.0 x 2.0 mol% are synthesized using melt-quenching technique and the influence of Eu2O3 content on their UV-Vis absorption properties are examined. The absorption spectra reveal two prominent peaks centered at 464 and 533 nm corresponding to 7F05D2 and 7F15D1 transitions, respectively. The optical band gap energy for direct and indirect transitions are found to be in the range of 3.294-3.173 eV and 3.067-2.971 eV, respectively. The decrease optical band gap energy with the increase of Eu2O3 contents is attributed to the generation of non-bridging oxygen (NBOs). The increase in Urbach energy from 0.226-0.308 eV with the increase of Eu2O3 contents signifies the variation in disorder and compactness of the glass network.

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

LINEAR AND NONLINEAR INTERSUBBAND OPTICAL ABSORPTION OF FINITE AND INFINITE SEMI-PARABOLIC QUANTUM WELLS

2011 ◽  
Vol 25 (07) ◽  
pp. 497-507 ◽  
Author(s):  
M. J. KARIMI ◽  
A. KESHAVARZ ◽  
A. POOSTFORUSH
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Optical Absorption ◽  
Quantum Well ◽  
Quantum Wells ◽  
Resonant Peak ◽  
Energy Eigenvalues ◽  
Finite Case ◽  
Infinite Case ◽  
Index Changes

In this work, the optical absorption coefficients and the refractive index changes for the infinite and finite semi-parabolic quantum well are calculated. Numerical calculations are performed for typical GaAs / Al x Ga 1-x As semi-parabolic quantum well. The energy eigenvalues and eigenfunctions of these systems are calculated numerically. Optical properties are obtained using the compact density matrix approach. Results show that the energy eigenvalues and the matrix elements of the infinite and finite cases are different. The calculations reveal that the resonant peaks of the optical properties of the finite case occur at lower values of the incident photon energy with respect to the infinite case. Results indicate that the maximum value of the refractive index changes for the finite case are greater than that of the infinite case. Our calculations also show that in contrast to the infinite case, the resonant peak value of the total absorption coefficient in the case of the finite well is a non-monotonic function of the semi-parabolic confinement frequency.

Defects in Divided Zinc−Copper Aluminate Spinels:  Structural Features and Optical Absorption Properties†

2007 ◽  
Vol 46 (10) ◽  
pp. 4067-4078 ◽  
Author(s):  
Anne Le Nestour ◽  
Manuel Gaudon ◽  
Gérard Villeneuve ◽  
Marco Daturi ◽  
Ronn Andriessen ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Structural Features ◽  
Absorption Properties ◽  
Copper Aluminate

SYNTHESIS AND SPECTROSCOPY OF SOME QUATERNARY OXYFLUORIDE GLASSES DOPPED WITH COPPER

2013 ◽  
Vol 22 ◽  
pp. 284-291 ◽  
Author(s):  
CH. SRINIVASU ◽  
M. A. SAMI ◽  
A. EDUKONDALU ◽  
SYED RAHMAN
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Copper Ions ◽  
Wave Length ◽  
Broad Band ◽  
Spin Hamiltonian Parameter ◽  
Band Gap Energy ◽  
Site Symmetry ◽  
Optical Absorption Spectra ◽  
Absorption Data

Electron paramagnetic resonance (EPR) and optical absorption spectra of copper ions in xLiF-(50-x)Li2O-20SrO-30Bi2O3 glass system have been studied. MDSC studies showed that the glass transition temperature decreases with LiF content. Optical absorption spectra of the pure glasses reveled that the cut off wave length increased and optical band gap energy decreased with increase in LiF content. EPR spectra of all the glass samples exhibit resonance signals characteristic of Cu2+ ions. The Cu2+ ions are in well-defined axial sites but subjected to small distortion leading to the broadening of the spectra. The spin-Hamiltonian parameter values indicate that the ground state of Cu2+ is d x2 y2 and the site symmetry around Cu2+ ions is tetragonally distorted octahedral. The optical absorption spectra exhibited a broad band corresponding to the d-d transition bands of Cu2+ ion. By correlating EPR and optical absorption data, the bond parameters are evaluated from various techniques.

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