Erbium (Er3+)-doped glass materials have been widely studied for their applications in broadband optical amplifiers and solid-state laser media due to their characteristic emission near 1.5 mu m. In this work, a series of gadolinium oxyfluoride phosphate glasses doped with Er3+ ions were synthesized via the conventional melt-quenching method at 1200 degrees C using alumina crucibles. The effects of alkali fluorides (NaF and KF) on the physical, structural, and optical properties of the glasses were systematically investigated. The density and refractive index values were increased when NaF and KF were added to the glass composition. Structural properties like FTIR and XANES spectra were analyzed. All glass samples showed a +3 oxidation state at similar to 8363 eV in the Er L-III-edge white line XANES spectra. Absorption spectra were obtained to analyze J-O parameters and gain coefficients for promising laser applications. The intense emission was shown in the peak of 1.53 mu m excited by 980 nm due to I-4(13/2) -> I-4(15/2) transition. The PLAfNfGdEr(1.0) glass showed the J-O parameter trendline Omega(2)>Omega(6)>Omega(4) and a stimulated emission cross-section of 2.42 x 10(-20) cm(2), which is greater than another present glass. Due to its broad emission profile centered at approximately 1.53 mu m and larger Er3+ ion-stimulated emission cross-section, this material presents a potential for broadband optical amplifiers in the C band.
Dy3+-doped Lu2.5Y0.5(Al2.5Ga2.5)O-12 (LuYAGG:Dy3+) single crystals were successfully grown by the optical floating-zone technique, and their structural, optical, and scintillation properties were systematically investigated as a function of Dy3+ concentration (0.5-10 mol%). X-ray diffraction confirmed that all compositions crystallized in a single-phase cubic garnet structure with high crystalline and without secondary phases. Optical transmittance spectra showed excellent transparency (similar to 80 %) and distinct Dy3+ absorption features corresponding to 4f-4f transitions and an O2- -> Dy3+ charge-transfer band in the UV region. Photoluminescence and excitation spectra revealed two characteristic emissions at similar to 484 nm (F-4(9/2) -> H-6(15/2)) and similar to 580 nm (F-4(9/2) -> H-6(13/2)), with the strongest emission observed at moderate Dy3+ concentrations. The decrease in PL intensity, quantum yield, and decay in lifetime at higher dopant levels confirmed concentration quenching via cross-relaxation and self-absorption. Normalized radioluminescence spectra under X-ray excitation exhibited identical Dy3+ emission bands across all samples, indicating consistent emission mechanisms independent of doping level. However, pulse-height and light-yield measurements identified the 2 mol% Dy3+ crystal as exhibiting the most efficient scintillation response (similar to 6000 ph/MeV, similar to 73 % of Bi4Ge3O12), consistent with optimal energy transfer and minimized non-radiative losses. The millisecond-scale scintillation decay reflected 4f-4f transitions typical of Dy3+, suggesting its suitability for applications prioritizing high stability and sensitivity over fast timing, such as radiation dosimetry and low-count-rate gamma-ray detection.
The preparation and characterization of glasses with BaO-Gd2O3-P2O5-CeF3 system were proceeded in this work for scintillator material. Glass density tends to decrease while the molar volume increases with CeF3 addition. Glasses strongly absorb photons in UV region with redshift of absorption edge but it has high transmittance for visible light. The optimum CeF3 concentration is 0.50 mol% which Ce3+ in glass exhibit the strong photoluminescence around 332-338 nm under direct Ce3+ excitation and Gd3+- Ce3+ energy transfer. The photoluminescence decay time of Ce3+ tends to increase by adding CeF3 that value of 0.50 mol% doped glass is short around 27 ns. X-rays induced luminescence spectra exhibit the similar pattern to that of photoluminescence spectra with Gd3+ -> Ce3+ energy transfer. The integral scintillation efficiency of 0.50 mol% doped glass is around 42 % compared to BGO crystal. This glass was operated in the practical X-ray imaging which created the quality image by a spatial resolution of 37.6 LP/mm. The developed glass owns high luminescence potential for using as a scintillator in X-ray detector and imaging applications.
A series of mixed silicate-phosphate glasses co-doped with Gd3+/Tb3+ ions at varying Tb concentrations were successfully synthesized using the melt-quenching technique. Their physical, optical and luminescence properties were analyzed, with an emphasis on the role of Tb3+ concentration. The photoluminescence (PL) spectra exhibit characteristic emission bands corresponding to Gd3+ and Tb3+ ions. A gradual decrease in the Gd3+ emission intensity at 311 nm is observed, accompanied by the suppression of Tb3+ emissions originating from the 5D3 level. In contrast, a significant enhancement of the green emission associated with the Tb3+ 5D4 -> 7Fj transitions is clearly evident. Under X-ray excitation, the radioluminescence (RL) spectra of the glasses displayed multiple sharp emission peaks corresponding to Tb3+ transitions, in contrast to the broad 478 nm emission band of the BGO crystal. Integral RL intensity ratios were demonstrated; all glasses exhibit significant radioluminescence intensity under X-Ray excitation compared to BGO, with QSPCaBaGd5Tb2.0 showing the highest performance reaches up to 52.09% in the 350-800 nm range. These results, together with X-ray imaging capability, demonstrate that the developed glasses are promising candidates for cost-effective scintillation applications.
Ce-doped phosphate, silicophosphate and germanophosphate glasses with the composition 25Li(2)O+ 10ZnO+ 5Gd(2)O(3)+xR+ (59.5-x)P2O5+ 0.5CeF(3) (x = 0, 10 mol%; R = SiO2 and GeO2) were prepared by the conventional melt quenching. This study highlights the novel role of network modification (SiO2 and GeO2 substitution) in enhancing the scintillation and imaging performance of Ce3 + -activated phosphate-based glasses; this topic remains inadequately researched. Structural analyses (FTIR, Raman) demonstrated that network modifications influence density and optical properties, with germanophosphate showing the highest density (3.07 g/cm(3)) and high transparency of around 80%. Notably, silicophosphate glass exhibits similar to 12 times higher photoluminescence intensity than phosphate glass, with an experimental quantum yield of 24.8%. Under X-ray excitation, strong emission bands were observed from Gd3+ (310 nm) and Ce3+ (similar to 337 nm). The integrated ratio of radioluminescence (RL) emission was calculated and followed the order silicophosphate > phosphate > germanophosphate, indicating optimal luminescence enhancement via Si incorporation. The superior scintillation response of the silicophosphate glass is further validated by pulse height measurements under Am-241 alpha-ray excitation. Silicophosphate glass was selected for its superior scintillation response, further confirmed by 2D/3D imaging and line-pair (MTF and contrast) analyses, demonstrating its suitability for ultra-high-resolution synchrotron X-ray imaging applications.
