Emission Spectra Of Glasses Research Articles

TB3+ CONCENTRATION EFFECT ON THE PHOTO - AND RADIOLUMINESCENCE RESULT OF LANTHANUM BORATE GLASS FOR YELLOWISH GREEN LASER APPLICATION

The melt-quenching technique was used to prepare lanthanum borate glass doping with Tb3+ (LBTb) to investigate physical and luminescent characteristics. The result more a concentration of doped terbium increases the glass density, molar volume, and refractive index. The higher Tb2O3 concentrations in glasses led to an increase of absorbance in the VIS and NIR range. The emission spectra of glasses were recorded at excitation wavelengths of 228 and 377 nm, and it was found that these glasses emit yellowish-green light. Tb3+ doped glass exhibited the highest intensity at 544 nm. The optimal concentration of terbium with the most significant emission in LBTb glass is 7 mol%, whereas decay time decreases as Tb2O3 content increases. The PL measurement showed a similar pattern with the spectrum of RL emissions. Moreover, this glass performs an integral scintillation efficiency of 36.32% compared with BGO crystal. According to the CIE 1931 chromaticity, the LBTb emitted a yellowish-green color. Terbium-doped glasses have attractive potential to be used in yellowish-green lasers.

Eu3+ ions doped lithium aluminium gadolinium borophosphate glasses: Energy transfer, optical and luminescence behaviors for red emission material

Eu3+ ions doped Li2O–Al2O3–Gd2O3–B2O3–P2O5 glasses have been prepared by melt quenching and characterized for their physical, optical and luminescence properties. Judd-Ofelt (JO) theory is used to evaluate the oscillator strengths and the three intensity parameters (Ωλ, λ = 2, 4 and 6) of the glasses. The radiative properties such as radiative transition probabilities (AR), radiative lifetimes (τ), branching ratios (β) and emission cross-section (σe) have been calculated from the absorption spectra according to the JO theory. The scintillation properties of glasses could be measured by comparing emission spectrum under the X-ray induced luminescence with bismuth germanate (BGO). The Commission Internationale de l’Elcairage (CIE) chromaticity coordinates (x,y) were also evaluated from the emission spectra of glasses and values of glasses take part in the red region.

Visible and near-infrared emission and energy transition of Er3+-Pr3+-Yb3+ tri-doped lanthanum aluminium silicate glasses

In this study, Er3+-Pr3+-Yb3+ tri-doped lanthanum aluminium silicate glasses of various doping concentrations were successfully prepared using the conventional melting method. The visible and near-infrared emission properties of Er3+-Pr3+-Yb3+ tri-doped lanthanum aluminium silicate glasses under excitations at 455, 520, and 976 nm were investigated. Moreover, the upconversion (UC) emission spectra of glass under excitation by the 980 nm laser were also investigated. The results showed intense emission bands centered at the visible and near-infrared emission ranges. In addition, the energy transition process between Er3+ and Pr3+ was discussed, and the role of Yb3+ in enhancing the absorption and emission of this system was demonstrated.

The Radioluminescence Investigation of Lead Sodium Borate Glass Doped with Eu3+

The effect of Eu3+-doped lead sodium borate glasses in composition of (79-x)B2O3: 20Na2O: xPbO: 1Eu2O3 and x are 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 55 mol%) were studied by using the melt-quenching technique. The absorption spectra show a maximum of 5 transition, where the strongest absorption bands were shown at 394 and 2101 nm in visible light and near-infrared region, respectively. The emission spectra of glasses were measured at 394 nm excitation wavelength. The highest peak of emission spectra corresponding due to 5D0 to 7F2 transition centered at 613 nm. The intensity of emission spectra increased with the increasing of PbO concentration upto 5 mol%. The radioluminescence spectrum (RL) has four peaks similar to photoluminescence, While, the transition at 612 nm strong strongest, identified at 0 mol% of PbO. In addition, the calculated integral scintillation efficiency of 5 mol% is 5.37% as compared with BGO crystal. The values of the color chromaticity coordinates were (0.65, 0.35) locating on the orange region of CIE diagram.

Lithium cadmium phosphate glasses doped Sm3+ as a host material for near-IR laser applications

Abstract Sm2O3 doped Lithium Cadmium Phosphate (LCP) glasses are synthesized by a classical melting method, and their molecular structures are investigated by X-ray Diffraction method (XRD). FT-IR spectra, UV–Vis–NIR spectra, and emission spectra of these glasses are collected and analyzed. The emission spectrum of the present glass shows four emission lines at wavelengths of 562 nm, 598 nm, 645 nm, and 706 nm. The dependence of electronic polarizability and optical basicity of the synthesized glasses on the refractive index and bandgap is investigated. Judd-Ofelt theory is used to evaluate oscillator strengths and JO intensity parameters of Sm3+-doped LCP glasses. The emission and absorption cross-sections of the 562 nm line, which is originated from 6P3/2 → 6F5/2 transition, are calculated. Other emission spectral lines (598 nm, 645 nm, and 706 nm) couldn't be originated from transitions to the ground level. This is due to the weakness of the absorption transitions in this spectral region, i.e., 550 nm–900 nm. The most probable suggestion that these lines are originated from the transitions 4G9/2 → 6F1/2, 4G9/2 → 6F5/2, and 6P3/2 → 6F11/2. Emission and absorption cross-sections of some transitions in the Near-infrared spectral region are evaluated. Laser gain of the 1.1 μm and 1.2 μm emission lines are obtained, where a positive gain is observed at population factors (P) ≥ 0.6 .

Fluorescence line narrowing and Judd-Ofelt theory analyses of [formula omitted]-doped low-silica calcium aluminosilicate glass and glass-ceramic

Eu-doped calcium aluminosilicate glass and glass-ceramic were synthesized and studied by site-selective spectroscopy. Using both broadband excitation and fluorescence line narrowing techniques, the D05→F17 emission transition was studied under resonant excitation at different wavelengths within the F07→D05 band. In order to explore the local structure of the systems, crystal-field analysis was applied assuming C2v site symmetry. Moreover, from the emission spectra of glass and glass-ceramic systems, Judd-Ofelt parameters Ωt (t = 2, 4) were considered. Transition probability (A), stimulated emission cross-section (σ), radiative lifetime (τR) and branching ratios (β) due to the transition D05→FJ7 (J = 1, 2, 3 and 4) of Eu3+ ions were evaluated in different local fields and their relative variations were discussed. The crystallization process, which converted the glass into glass-ceramic, promoted an important enhancement in the quantum efficiency, which was improved from 45% to 60%.

Luminescence properties and Judd-Ofelt analysis of Sm3+ doped lithium aluminium phosphate glasses

Lithium aluminium phosphate glasses doped with samarium oxide were prepared by melt-quenching technique and investigated their physical, optical and luminescence properties. The result of physical properties indicated that the density and the molar volume of glass samples were increased with an increase of Sm2O3 content. The absorption spectra of glass samples were recorded in the wavelength range of 250-2000 nm, these glasses have shown strong absorption bands in the visible (Vis) and near-infrared (NIR) region at 401 and 1232 nm. The emission spectra of glasses, excited with 401 nm excitation wavelength showed four emission bands centered at 561, 597, 644 and 704 nm. From Judd-Ofelt analysis, the J-O parameter (Ω2, Ω4, Ω6), radiative transition possibility (AR), stimulated emission cross-section (σ(λp)) and branching ratios (βR) were indicated that the glass samples an interesting potential for using glass as laser medium with 597 nm emitting.

Physical and optical properties of lithium borosilicate glasses doped with Dy3+ ions

The borosilicate glasses with Dy3+ ions were prepared by the melt quench technique with varying concentration of Dy2O3. The glasses were characterized by the density calculation, absorbance and photoluminescence (PL) spectroscopy measurements. Density and molar volume of the glasses increases with increase in Dy3+ ions in the glass matrix. This behavior is correlated with the higher molecular weight and larger ionic radius of Dy3+ ion compared to the other constituents of glass matrix. Emission of Dy3+ doped glasses showed three bands at 482, 573 and at 665nm which correspond to 6H15/2 (blue), 6H13/2 (yellow) and 6H11/2 (red) transitions. The emission spectra of glasses with different concentration of Dy3+ ions shows that, glasses with 0.5mol% of Dy2O3 shows highest emission and decreases with further doping. CIE 1931 chromaticity diagram showed that the emission of these glasses was in the white region. Photographs of these glasses under 349nm Light emitting diode excitation also confirmed the white light emission from these glasses.

Effect of Nd<sup>3+</sup> Ion on Bismuth Borosilicate Glass Properties

This paper reports neodymium doped bismuth borosilicate glasses in composition (40-x)B2O3-40Bi2O3-20SiO2-xNd2O3 where x = 0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%, have been prepared by melt quenching technique and are characterized through physical properties structural properties, optical absorption spectra and emission spectra measurements. The density is found to increase with the increase in concentration of Nd2O3. The molar volumes of glass decrease where concentration of Nd2O3 where concentration of Nd2O3 is 0-0.5 mol% and beyond 0.5 mol% that molar volumes were increased. The absorption spectra of Nd3+-doped glass centered at 512 nm (4I9/2→2K13/2+4G9/2), 526 nm (4I9/2→4G7/2), 584 nm (4I9/2→4G5/2+2G7/2), 625 nm (4I9/2→2H11/2), 681 nm (4I9/2→4F9/2), 747 nm (4I9/2→4F7/2+4S3/2), 804 nm (4I9/2→4F5/2+2H9/2) and 877 nm (4I9/2→4F3/2) have been observed. The emission spectra of glass were also investigated.

Physical, Optical and Luminescence Properties of Er<sup>3+</sup>-Doped Bismuth Borosilicate Glasses

Er3+-doped bismuth borosilicate glasses (Bi2O3+B2O3+SiO2+Er2O3) glasses doped with different Er2O3 concentrations (0, 0.50, 1.00, 1.50, 2.00, 2.50 mol%) have been prepared by melt quenching technique and their physical, optical and luminescence properties have been studied. The density of glasses showed the highest value at 4.7358 g/cm3 with 1.00 mol% of Er2O3. The optical absorption spectra of glasses were observed seven bands at 488, 523, 543, 654, 801, 975 and 1529 nm which assigned to the transitions 4I15/2→4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2, 4I11/2 and 4I13/2, respectively. The emission spectra of glasses were also investigated and discussed in term of energy level of Er3+ ion in glass matrices.

Multi-photon luminescence in Er 3+/Yb 3+:SrO⋅TiO 2 glass ceramic

Er 3+/Yb 3+ doped strontium titanate borosilicate glass was prepared. Glass ceramic was prepared by controlled heat treatment (at 955 °C) of glass. Ti 10O 19 and Sr 3Ti 2O 7 were found as major crystalline phases. The emission spectra of glass and glass ceramic samples were investigated under 976 nm laser excitation. In glass ceramic, the intensity of the emitted radiation was much higher (≈50 times for green and ≈10 times for red emission) than in the glass. A new three photon process was found to be responsible for emission at low power which is not yet observed in Er 3+/Yb 3+:SrO⋅TiO 2 glass ceramic system to the best of our knowledge. The details of upconversion mechanisms e.g. Energy Transfer (ET) and Excited State Absorption (ESA) were studied by power-intensity log dependence. It is expected that Er 3+/Yb 3+ doped nanocrystalline (⩽10 nm) Sr 3Ti 2O 7 phase was responsible for the observed upconversion phenomenon in glass ceramic.

The role of trapped electrons e -vis and e -ir in low temperature luminescence of aqueous solutions. A pulse radiolysis study

Correlation has been studied between the yields of e - ir and e - vis determined by pulse absorption measurements in the temperature range 6–110 K for CaCl 2, MgCl 2 and LiCl glasses and the luminescence generated in these matrices. Emission spectra of glasses at the temperatures 6, 20, 50, 80, 110 K and their time evolution were recorded. It has been found that the decay of luminescence at 6 K may be well correlated with the decay of the e - ir band. This indicates the participation of e - ir in low temperature recombination luminescence not only in LiCl and MgCl 2 but also in CaCl 2 ice. At higher temperatures radiative recombination involves also (e - vis) Ca 2+ (50 K) and (e - vis) Mg 2+ (110 K). The results obtained may be interpreted by using the model of traps based on ionic lattice the postulated by us previously. They also add some information as to the early behaviour of electrons in condensed systems.