Host Glass Research Articles

Adhesion of Silicate Impact Melts on Impact Glasses of Chang'e‐5 Regolith

AbstractMicroscopic silicate melts are ubiquitous on surfaces of lunar regolith particles, and they record physicochemical processes of regolith reworking on the Moon. Similar microstructures are visible on surfaces of the Chang'e‐5 lunar impact glass particles, which are predominantly sourced from local mare deposits. Therefore, the microscopic silicate melts provide an invaluable opportunity to study the movements, provenances, and chemical alterations of substances involved in regolith reworking. However, the small lateral sizes and thicknesses of the surface silicate melts are a challenge for quantifying their internal structures and geochemical compositions, hampering interpretations of their origin. Here we report structural and geochemical characteristics for microscopic silicate pancakes, domes and foams on surfaces of Chang'e‐5 impact glass particles. Based on the contact and compositional differences between the surface microscopic silicate melts and their host glass, we reveal that these microstructures are consistent with being formed during impact bombardment in regolith via adhesion of impact melts to earlier‐existing glasses. Most of the microscopic silicate melts have minor compositional differences with the host glass. Our mixing calculations for compositions of impact melt formed from various proportions of local regolith minerals at the landing site reveal a dominant precursor from the local mare deposits. Few portions of the microscopic silicate melts have exotic compositions that are different from the local regolith materials, confirming that ejecta from the other geochemical terrains is minor at the landing site. Our results show that regolith formation and reworking at the Chang'e‐5 sampling site mainly involved local mare deposits.

Impacts of hydroxyl and bond energy on laser‐induced damage in mid‐infrared chalcogenide glass

AbstractMid‐infrared chalcogenide glasses often suffer from a low laser damage threshold due to their weak bond energy and the presence of impurities, particularly at the specific wavelength of 2.94 µm, which is widely used in medical applications. In this paper, we first investigated the effect of the hydroxyl (OH⁻) peak absorption coefficient on the laser damage properties of As2S3 glasses. The surface temperature distribution of chalcogenide glasses under laser irradiation was also analyzed using the finite element method (FEM) and in‐situ heat monitoring. The results showed that the surface temperature of the glass increases exponentially with the rise in the absorption coefficient at the OH− peak position. Subsequently, Raman spectra analysis and average bond energy (ABE) theory were employed to compare five typical chalcogenide glasses without hydroxyl absorption, revealing the relationship between the laser damage threshold and the bond energies of the glass networks. Finally, an optimized glass composition of Ge25As10S65 was identified, possessing the highest laser damage threshold of 340.98 J/cm2, more than twice that of traditional As2S3. These findings provide essential glass host and data references for the future development of mid‐ and far‐infrared optical fibers and waveguide devices.

A Review of the Physical, Optical and Photoluminescence Properties of Rare Earth Ions Doped Glasses

Doping glasses with rare-earth ions have garnered significant attention among researchers worldwide. This interest stems from the widespread utilization of rare-earth ions to enhance the optical characteristics of host glasses and exploit the unique spectroscopic properties arising from their optical transitions in the intra-4f shell. Thus, this study reviewed the exceptional potential of rare-earth ion-doped glasses (REIs) in various applications such as solid-state lasers, photonic devices, communication optical fibers, and white light emission. Various methods for the fabrication of glass such as direct melt quenching, sol-gel, ion exchange, sputtering and co-doping techniques were reviewed extensively. The Specific focus was on the physical, optical and photoluminescence properties of glasses produced from glass formers co-doped with rare earth ions. The investigation centers on the comprehensive current applicability of REI-doped glasses. The review concludes based on the physical, optical and photoluminescence properties of rare earth ion-doped glasses that they are extremely useful in photonics, lasers, biomedical and optical communication applications.

High-efficiency 1.6 μm-band fiber laser based on single Er3+-doped tungsten tellurite glass with high mechanical strength through tailored glass network

In this study, the correlation between the Raman structure, thermal stability, and mechanical properties of TeO2-ZnO-La2O3–WO3 glasses with varying WO3 contents are systematically established. By exploring the critical point in the transformation process of glass network structural units, the optimal glass components of 74TeO2-12ZnO-5La2O3–9WO3 glass possess the maximum thermal stability (158 °C) and the highest mechanical properties at the same time. The maximum Vicker hardness and Young's modulus of the optimal glass can reach up to 4.007 GPa and 56.212 GPa, which are higher than those of the well-known TeO2-ZnO-Na2O (TZN) and TeO2-ZnO-La2O3 (TZL) glasses. Furthermore, the 0.5 mol% Er3+-doped glass at this critical point (TZLW-0.5Er) exhibits a higher laser figure of merit (54.29 × 10−21 cm2 ms), a larger laser gain bandwidth value (116 nm) and higher emission cross-sections at 1600 nm (2.52 × 10−21 cm2) and 1625 nm (1.06 × 10−21 cm2) than other host glasses. Finally, high-efficiency laser outputs at 1600 and 1625 nm based on TZLW-0.5Er glass fiber are successfully achieved by simulation. These results show the greater practical potential of TZLW-0.5Er glass with higher mechanical strength compared to TZN and TZL fibers for the 1.6 μm-band laser.

A multi-function glass shield for neutrons and gamma rays of boron- and bismuth-reinforced silicate glass

A successful attempt to produce a multi-function glass shield for attenuating neutrons and gamma rays by reinforcing a silicate glass network with boron and bismuth has been accomplished. A composition of 20SiO2-80Na2O (BSiBi0) was proposed to be used as a host glass network and prepared using the melt/annealing techniques. The low concentration of SiO2 in BSiBi0 was not sufficient to form a stable glass network. Then, the proposed BSiBi0 was modified with 10, 20, 30, and 40 mol% of each of B2O3 and Bi2O3 (BSiBi1, BSiBi2, BSiBi3, and BSiBi4) simultaneously. The structural effects of adding B3+ and Bi3+ were studied through X-ray diffraction, density, and FTIR, which all showed enhancement of glass forming ability, a former role of Bi3+ ions, and crowded the glass network by BO4 units. The derived structural parameters -\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-$$\\end{document} molar volume, mean silicon – silicon separation, mean boron – boron separation, oxygen packing density, packing density, and number of bridging/non-bridging oxygen -\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-$$\\end{document} were extensively discussed to explore the impact of B3+ and Bi3+ on the formed network. The richness of the proposed host glass network by B3+ and Bi3+ enhanced its thermal stability. The obtained elastic properties by ultrasonic measurements reflect the increase of the glass rigidity with increasing concentrations of B3+ and Bi3+ ions. The obtained glasses have high visible light transparency and almost complete UV absorption. The measured shielding parameters against two types of neutron energies (total slow and slow) and a wide range of gamma rays’ energies showed a significant improvement in the shielding efficiency of the considered glasses. The total slow neutrons, slow neutrons, and gamma rays’ attenuation abilities were improved by 22.9, 135.5, and 73.8 -\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-$$\\end{document} 199.5%. High thermal stability, elasticity, visible light transparency, and neutrons and gamma rays’ attenuation performance features give the produced glasses, especially BSiBi4 glass, preference as shielding materials in nuclear fields.

A closer look at the fabrication of some doped metal ions in borophosphate glass system and their structural, elastic, optical, and gamma-ray shielding characteristics

Borophosphate host glasses doped with zinc oxide (ZnO), titanium dioxide (TiO2), tellurium dioxide (TeO2), or cerium oxide (CeO2) were synthesized using rapid quenching techniques. Fourier transform infrared (FTIR) spectra, along with deconvoluted FTIR spectra, were recorded in the 400–4000 cm−1 range. Using the models of Tauc and Urbach, the optical energy band gaps of these glasses were found to be 3.212, 3.289, 3.262, 3.087, and 2.475 eV respectively. Due to the incorporation of different metal ions into the prepared glasses, the density increased and the molar volume decreased, making the glass structure highly compact. Since the elastic moduli are directly related to the average cross-link density, the shear and longitudinal moduli show a forward proportionality with the average cross-link density. Detailed reporting focused on the mass attenuation coefficients (μm) and exposure build-up factors (EBF), crucial for evaluating the shielding properties of the material within the energy range of 0.015–15 MeV and penetration depth up to 40 mean free paths (mfp). Glass samples doped with tellurium dioxide exhibited the highest gamma attenuation due to their higher effective atomic number compared to the other samples. Compared to Portland concrete, the prepared glass composites showed higher mass attenuation coefficients across the entire investigated energy range. These results suggest that although Borophosphate glasses doped with cerium oxide have preferred mechanical properties compared with the other prepared glasses, Borophosphate glasses doped with tellurium dioxide could serve as transparent shielding material for medical applications due to their higher attenuation coefficient.

Unlocking the secrets of colored glass: Structural-optical behaviors and non-linear optical properties of [formula omitted] and [formula omitted] ions-doped borates

Investigations of structural-optical properties were performed for La3+-doped borate glass host based on a fixed ratio of Fe3+ ions, and within a lanthanum oxide concentration range of (0–8 mol%). The density was measured and confirmed the increase in bond density of the network, with increasing its volume. While infrared spectroscopy was carried out to investigate the dominant role of lanthanum on structural variations of glass, for example, the BO3 to BO4 conversion and the conspicuous decrease in NBO content. Optically, the d-d visible transitions of Fe3+ ions were suppressed by La3+ quenchers, preventing their peaking within the optical absorption spectra of glass samples. Further, in good coalescence with density and infrared spectroscopy results, Tauc gap energy increased with lanthanum oxide addition owing to the band structure modulations. Additionally, the metallization criterion changed from 0.262 (eV)0.5 to 0.325 (eV)0.5, owing to the Tauc gap energy increment, indicating that the lanthanum addition causes a shift toward the semiconducting nature of the prepared samples. On the other hand, Urbach energy decreased with increasing lanthanum oxide content, manifesting the glass structure's propensity toward less disorder and high polymerization. Besides, the increase in electron-phonon interaction energy indicates a high possibility of phonon consumption to bind free electrons as pairs, mitigating the network disorder. Surprisingly, the non-linear optical properties of the glass matrix were enhanced through lanthanum oxide addition. For the current glass host activated by La3+ ions, including Fe3+ color centers, the correlation between these above-mentioned structural modifications, and optical findings provide a decent paradigm for the optics realm.

Compositional impacts of high CdO content on the structure and radiation shielding efficiency of CoO–Na2O–B2O3 glass system

Here, this study investigated the structural changes and radiation shielding efficiency of a borate glass host modified by varying cadmium oxide (CdO) concentrations. The glass composition consisted of boron oxide (B2O3; 80:56 mol%), sodium oxide (Na2O; 19.6 mol%), and cobalt oxide (CoO; 0.4 mol%), with cadmium oxide (CdO; 0:24 mol%). The glass structure was analyzed utilizing mass density and FT-infrared spectroscopy (FTIR) in the 400 to 1600 cm−1 range, while radiation shielding properties were investigated utilizing the online Phy-X software in the 0.284–1.333 MeV energy window. Notably, the addition of CdO significantly impacted the glass density, increasing it by approximately 93 % as the added CdO concentration rose from 0 to 24 mol% (i.e., from 2.507 g/cm3 to 4.849 g/cm3). FTIR analysis revealed a concurrent increase in BO4 structural units with increasing CdO/B2O3 ratios. This observation was supported by the calculated N4BO4/(BO3+BO4) ratio, which increased from 40.73% for the CdO-free sample to 52.00% for the highest CdO content. This increase in BO4 units, denser than BO3 units, explains the observed density increase. Conversely, the concentration of non-bridging oxygens decreased from 10.14% to 4.34% with increasing CdO contents, indicating a more tightly packed glass network. Radiation shielding studies demonstrated that increasing CdO concentration from 0 to 24 mol% enhanced the shielding efficiency, evidenced by a decrease in the half-value layer parameter (HVL). The radiation protection efficacy (RPE) also increased from 0.214 to 0.426 for the CdO-free sample to the sample containing 24 mol% CdO at the investigated energy level. This finding highlights the superior shielding capability of the CdO-rich sample. Furthermore, the transmission factor (TF) was investigated for a constant thickness of 0.75 cm for glasses. The CdO-rich sample exhibited a lower TF compared to the CdO-free sample, particularly at lower energies. This finding confirms that, for a given thickness and energy, raising the cadmium oxide content in the current composition leads to an observed mitigation in the transmitted radiation.

Er3+/Yb3+ Co-Doped Fluorotellurite Glass Fiber with Broadband Luminescence.

In order to address the 'capacity crisis' caused by the narrow bandwidth of the current C band and the demand for wide-spectrum sensing sources and tunable fiber lasers, a broadband luminescence covering the C + L bands using Er3+/Yb3+ co-doped fluorotellurite glass fiber is investigated in this paper. The optimal doping concentrations in the glass host were determined based on the intensity, lifetime, and full width at half maximum (FWHM) of the fluorescence centered at 1.5 µm, which were found to be 1.5 mol% Er2O3 and 3 mol% Yb2O3. We also systematically investigated this in terms of optical absorption spectra, absorption and emission cross-sections, gain coefficients, Judd-Ofelt parameters, and up-conversion fluorescence. The energy transfer (ET) mechanism between the high concentrations of Er3+ and Yb3+ was summarized. In addition, a step-indexed fiber was prepared based on these fluorotellurite glasses, and a wide bandwidth of ~112.5 nm (covering the C + L bands from 1505.1 to 1617.6 nm) at 3 dB for the amplified spontaneous emission (ASE) spectra has been observed at a fiber length of 0.57 m, which is the widest bandwidth among all the reports based on tellurite glass. Therefore, this kind of Er3+/Yb3+ co-doped fluorotellurite glass fiber has great potential for developing broadband C + L band amplifiers, ultra-wide fiber sources for sensing, and tunable fiber lasers.

An advanced fabrication method for Yb3+-Doped optical fibers featuring AlPO4 core glass

Ytterbium (Yb)-doped fibers using aluminophosphosilicate (Yb-APS) host glass offer significant advantages over conventional aluminosilicate (Yb-AS) fibers, such as strong photodarkening resistance, higher RE-ion solubility and lower Numerical Aperture (NA), making them ideal for high-power laser applications. However, achieving optimal performance in Yb-APS fiber fabrication poses various challenges, including maintaining a precise Al3+/P5+ ratio (1:1), minimizing the central dip in the refractive index profile (RIP), ensuring proper dopant distribution, and reducing background loss. We introduce a new fabrication method for Yb-APS fiber to address these challenges. This approach entails first synthesizing amorphous Yb³⁺: AlPO4 particles, then incorporating them into the fiber core using a hybrid technique that merges Vapor Phase Delivery (VPD) with solution doping (SD). We extensively utilized various materials and optical characterizations, including XRD, FTIR, Raman spectroscopy, FESEM, and XPS, to fine-tune the composition of Yb³⁺: AlPO4. The optical characterization of the developed preform sample, including absorption, emission, and luminescent lifetime measurements, was conducted to assess the fabrication technique's suitability. The results confirmed the successful incorporation of Yb-ions into the preform core, with peaks consistent with reported values. The fiber's attenuation loss was measured, showing approximately 10 dB/km at 1200 nm. This indicates that the particles dissolved smoothly during preform and fiber processing, resulting in minimal scattering loss in the fiber core. The developed fiber demonstrated NA of 0.1, uniform RIP along the preform length with significant reduction of the central dip formation and improved spectral performance (∼1.7X broader bandwidth) compared with an equivalent Yb-AS fiber. These findings suggest the Yb-APS fiber's overall effectiveness and structural robustness, highlighting the potential of the proposed fabrication method for high-power fiber laser applications.

Influence of Selenium Oxide on Structure and Properties of New Zinc Boroselenite Glasses

The traditional melt quenching method was used to prepare new zinc boroselenite glasses in the system xSeO2·(50 − x)ZnO·50B2O3 with varying SeO2/ZnO molar ratio. X-ray diffraction patterns (XRD) have revealed an amorphous structure in glasses of up to 40 mol pct SeO2. On the other hand, the presence of sharp diffraction peaks on the XRD spectra of samples containing 40 and 50 mol pct SeO2 confirms a formation of some polycrystalline phases distributed in the host glass network. Based on FTIR and NMR data, the glass structure at a short-range order exhibited a similar value of the fraction of tetrahedral boron (N4), particularly, for both samples of 0 and 5 mol pct SeO2. In this situation, SeO2 is as well as ZnO both played a modifier role. On the other hand, increasing SeO2 on expense of ZnO decreases the N4 fraction gradually. However, in SeO2-rich glass, most of boron atoms are mainly placed in three coordinated sites in BO3 units coordinated with SeO4 groups. Decreasing N4 fraction and increasing crystallization confirmed that SeO2 operates as a glass former and mainly as a crystalline agent. The results based on the TEM of the selected area of electron diffraction patterns (EDP) agree well with the ones obtained by XRD. The diffraction patterns clearly displayed two sets of diffraction rings: one is caused by boroselenite nanocrystals and the other by zinc selenite. In contrast, a broader halo of dispersed structure, known as an amorphous structure, is present in the diffraction pattern obtained from SeO2-free glass.

Photo and X˗ray induced luminescences of Eu3+˗doped sodium alumino boro˗tellurite oxyfluoride scintillating glass for X˗ray detecting material

The spectroscopy features of sodium alumino boro˗tellurite oxyfluoride glasses doped with various molar fractions of Eu2O3 ions (TBANEu) are studied through absorbance, excitation, emission, and decay curves. The excitation data are used following phonon side band spectroscopy to evaluate the phonon energy (1326 cm-1) of the glass host. The densities, molar volumes, and refractive indices, including the Ω2,4,6 parameters of fabricated glasses are studied. The magnitudes of laser properties like effective line widths, branching ratios, and emission cross˗sections obtained for the Eu3+:5D0→7F2 transition could be useful for reddish-orange lighting devices application. Additionally the quantum efficiency estimated from experimental and calculated lifetimes is about ˃ 70% for the 5D0 level luminescence of TBANEu glasses. Upon 395 nm radiation, the current glass system can exhibit color coordinates close to (0.647, 0.351) for reddish˗orange light as performed by the CIE1931 chromaticity diagram. The integral scintillation intensities of TBANEu glasses were determined using the X˗ray excitation and observed that the TBANEu20 glass showed a highest scintillation efficiency of 39%, resulting in scintillator and X˗ray sensing device applications.

Investigation of structural, physical and optical properties of sodium boro-tellurite glasses doped with iron oxide

In this work, we demonstrate systematic studies on the influence of Fe2O3 on the structural and optical properties of transparent B2O3–TeO2–Na2O glasses containing the different concentrations of Fe2O3. The glasses were prepared via the standard melt quenching method, and the prepared glasses were characterized using, XRD, electron paramagnetic resonance (EPR), FTIR, and UV–visible spectroscopic techniques. Furthermore, we evaluated several physical properties of the glasses, including densities, molar volume, boron-boron separation, and oxygen packing density, with respect to the concentration of Fe2O3 in the host glass matrix. It is observed that the density of the glasses and the average boron-boron distance found increase with Fe2O3 concentration due to the modification in the glass network induced by the dopant ions. EPR spectra reveals the presence resonance signals at g ∼2.04 and g ∼4.26, hence it proves the existence of Fe3+ in distorted octahedral coordination and supported by UV–Vis absorption bands. The FTIR spectra revealed an increase in spectral intensity with the concentration of Fe2O3. This was attributed to the formation of non-bridging oxygens through converting BO4 units into BO3 units, which Fe2O3 mediated. The UV–visible spectral analysis showed a decreased energy band gap from 2.26 to 1.51 eV with increased Fe2O3 concentration. Additionally, we determined the Urbach energy, refractive index, optical basicity, and electronegativity, which are presented in detail.

Structure and gamma attenuation behavior of copper ions in host glass from the system (P2O5–LiF–CaF2)

Copper-doped lithium calcium fluorophosphate glasses in the compositional system (60−x)P2O5·20LiF·20CaF2·xCuO (x = 0−3 mol%) were prepared using the conventional melt quenching technique. X-ray diffraction confirmed the amorphous, non-crystalline phase of the glasses. Optical absorption spectra indicated the presence of additional broad visible-NIR absorption bands upon CuO doping, attributed to distorted Cu2+ ions. Possible overlaps from Jahn-Teller distorted sites or clustering into nanodomains may contribute to band broadening. The direct optical bandgap was found to reduce from 3.89 eV to 1.17 eV with increasing CuO content. The study of physical parameters showed almost linear variation in density (2.62–2.95 g/cm3) and molar volume (40.45–35.29 cm3/mol) with incremental CuO substitution, explained by changes in structural packing efficiency and formation of Cu–O complexes. FTIR spectra revealed vibrations corresponding to phosphate structural groups. The simulation of radiation shielding parameters displayed steady improvements with higher CuO fractions, which were related to enhanced photon interactions via photoelectric absorption and Compton scattering.

Enhancing gamma-ray shielding with Bi2O3-Enriched BTBi glasses: Optimal balance of attenuation and glass transparency

A host glass of barium-magnesium-boro-tellurite (BTBi0) was produced and reinforced with 10, 20, 30, and 40 mol% of Bi2O3 (BTBi1, BTBi2, BTBi3, and BTBi4) to enhance its gamma rays shielding efficiency. The structural, optical, and attenuation properties of the produced BTBi glass series were studied. Penetration of Bi2O3 up to 30 mol% into the proposed host network enriches it with non-bridging oxygens (NBO) units, while the glass containing 40 mol% was enriched with bridging oxygens (BOs) units, which arose as a result of the role of the Bi3+ ion in disrupting the borate network, leading to the BO4⇋BO3 conversion. The conversion role of Bi2O3 was clearly evident in the behavior of the molar volume, oxygen packing density, and packing density. The results of Raman shift showed the formation of the structural units of the boro-tellurite network and BiO6 units within the glass network. The compositional changes brought about by Bi2O3 agreed perfectly with the results of the optical properties of the studied glass. The red shift in optical absorption spectra, the reduction in the optical band gap, and the augmentation of Urbach energy up to 30 mol% of Bi2O3 occurred mainly as a result of the formation of NBOs units. In contrast, at 40 mol% of Bi2O3, the continuation of the red shift, the decrease in the optical band gap, and the increase in the Urbach energy, despite the increase in BOs compared to the NBOs, are attributed to the high polarizability of Bi3+ and the formation of BiO6 units. The transparency of the glass increased to about 85 % with increasing Bi2O3 up to 30 mol%, but decreased to 70 % at 40 mol%. The ability of the considered glasses to attenuate gamma rays was examined using Phy-X/PSD software. The results showed that the attenuation ability improved significantly with increasing Bi2O3 concentrations, where the required thickness to attenuate gamma rays was reduced by 48.505–77.134 % at 40 mol% of Bi2O3. Based on the high attenuation ability and transparency of the studied BTBi glasses, they can be used as a protective shield against gamma rays in nuclear applications that require visual monitoring.

Synthesis of eco-friendly borosilicate glass with Eu3+ dopants: Harnessing recovered silica gel waste for reddish-orange emission materials

In this study, recovered silica gel waste (RSGW) is used as a key raw material to create borosilicate glass doped with Eu3+ ions in a new and environmentally friendly way. The glass compositions were fabricated using the melt quenching method, with different amounts of RSGW and a constant 1.0 mol% Eu3+ doping concentration. The study shows that increasing the doping concentration of RSGW improves the glass density and rigidity while reducing the molar volume, indicating enhanced glass stability. Photoluminescence and X-ray luminescence analyses confirm that the optimal composition with 50 mol% RSGW exhibits the strongest emission. Based on the phonon sideband analysis, the host glasses have a phonon energy of 966.53 cm− 1. An X-ray absorption near-edge structure (XANES) analysis showed that most of the europium ions were in the 3+ oxidation state. The CIE 1931 chromaticity investigation shows the x,y color coordinates at (0.645, 0.351) in the reddish-orange region. To optimize the doping concentration of Eu2O3, it was determined that a fixed concentration of 50 mol% RSGW created the most suitable mixture. Both luminescence emission spectra exhibit strong luminescence, with a peak emission wavelength of 615 nm (⁵D0→⁷F2), confirming concentration quenching in both photoluminescence and x-ray luminescence at a concentration of 1.0 mol%. The study explores potential applications of this novel material in photonics and suggests that this eco-friendly synthesis approach holds great promise for sustainable and efficient production of reddish-orange emission materials.

Exploring luminescence dynamics in Ce3+/Er3+ co-doped lithium zinc barium borate optical glasses: A study for advancing photonic technologies

Lithium zinc barium borate glasses were synthesized using the melt-quenching method and doped with Ce3+, Er3+, and their combination. The study examines the influence of Ce3+ on the photoluminescence of Er3+ in these glasses. X-ray diffraction confirmed the amorphous nature of both undoped and doped glasses, while Fourier-transform infrared spectroscopy showed the conversion of BO3 to BO4 units, and Raman spectroscopy indicated a phonon energy around 1136 cm−1. The Ce3+-doped glasses exhibited a blue emission at 447 nm due to the 5d→4f1 transition. Co-doping with Ce3+ and Er3+ led to decreased visible upconversion emissions but significantly enhanced near-infrared emissions at 1.53 μm. This enhancement is attributed to reduced non-radiative decay and improved energy transfer between Er3+ and Ce3+ ions, facilitated by the phonon energy of host glass. The 1.53 μm emission intensity in Ce3+/Er3+ co-doped glass was about 60% higher than in singly Er3+-doped samples, highlighting the potential of Ce3+ co-doping for broad amplification at 980 nm excitation.

Structural, optical properties, and laser spectroscopy of erbium-doped low-melting borate glasses

Glasses that contain Erbium oxide as a dopant exhibit garnered considerable interest for its use in photonic applications, primarily because of the intra-4f sublevel transitions of Erbium ions, which enable emission in the technologically significant 1.5 μm communications window. In this work, a series of Erbium oxide doped sodium lithium borate glasses were synthesized via melt quenching with compositions xEr2O3-(55-x)B2O3–25Li2O–10Na2O–5CaO–3SrO–2Al2O3 (x = 0, 1, 2, 3, and 5 mol%). An investigation was conducted to examine the consequences of Er3+ on the crystal structure and laser spectroscopy. Furthermore, the optical properties of the samples that were created. XRD analysis showed degradation of the glass network with increasing Er2O3 content due to disruption of boroxol rings. FTIR spectra indicated variations in BO3/BO4 ratios and Er–O vibrations with doping. Absorption spectra revealed characteristic Er3+ f-f transitions and a redshift in the UV edge. The bright field imaging proved the effect of Er3+ on the homogeneity of the surfaces. Meanwhile, 3D laser Raman mapping chemically proves the good distribution of Er2O3 on the glass surface. With an excitation under 980 nm, visible emissions at 550 and 660 nm, along with NIR emission at 1550 nm arising from Er3+ 4f levels, were observed. The results demonstrate that Er3+ doping effectively modifies the glass structure and optical properties. The borate glass host provides an excellent platform for customized erbium-doped photonic devices operating in the telecom C-band.

Thulium-doped titanate-germanate glasses for infrared photonics

In this paper, we performed a comparative spectroscopic analysis of Tm3+-doped glasses based on GeO2-BaO-Ga2O3 (GBG) and TiO2-GeO2-BaO-Ga2O3 (TGBG) to achieve broadband luminescence at 1.8 μm. Glasses were prepared at different doping concentrations (0.05 mol% and 1mol%) in order to investigate the effect of Tm3+ ions as well as host composition (GeO2:TiO2 molar ratios) on near-IR luminescence properties. We report on the hypersensitivity of the transition 3H6 → 3F4 of Tm3+ in a series of titanate-germanate glasses, which was shifted to longer wavelengths with increasing TiO2 concentration. The relative intensity of the main near-IR emission band corresponding to the 3F4 → 3H6 (1.8 μm) transition of Tm3+ was 4.8-fold enhanced for glass with molar ratio GeO2:TiO2 = 1:5 compared to GBG glass system. We observed the luminescence quenching phenomena for samples containing more than 0.5 mol% of Tm3+ ions. The calculated spectroscopic parameters, such as measured luminescence lifetime (τm) and the quantum efficiency (η), were discussed and compared to the different laser glasses. Importantly, luminescence decay curves have been examined using the Inokuti-Hirayama model. Additionally, the correlation between optical properties and local structure in glasses was well evidenced by Raman spectroscopy. The proposed strategy, in combination with various chemical composition of glass host activated by various Tm2O3 concentration, might be beneficial for modern near-infrared photonics.

Investigation the optical and structural properties of Mn-doped Sb2S3 nanocrystals embedded in host glass

The search for earth-abundant and non-toxic elements is essential for the manufacture of sustainable optical devices. In this context, dilute magnetic semiconductor (DMS) xMn-doped Sb2S3 nanocrystals (NCs) embedded in host glass were synthesized by the fusion method. Differential Thermal Analysis shows evidence of Sb2S3 phase crystallization peak and changes in glass transition and crystallization temperatures of the host glass with the presence of xMn-doped Sb2S3 NCs. Transmission electron microscopy images show the formation of xMn-doped Sb2S3 NCs with increasing size (2.1–3.8 nm) as a function of concentration (x = 0.00 to 0.40), respectively. X-ray diffraction measurements reinforced the evidence for the orthorhombic structure of xMn-doped Sb2S3 NCs embedded in glass. Energy dispersive X-ray spectroscopy analyses confirm the S, Sb and Mn precursor elements of DMS NCs. Atomic and magnetic force microscopy measurements show the magnetic contrast patterns resulting from the incorporation of Mn atoms into the Sb2S3 structure. The electronic paramagnetic resonance spectrum confirms the presence of Mn2+ ions (3d5) located in the crystal field of the Sb2S3 semiconductor due to six hyperfine transitions. The redshift of the Raman vibrational mode (1Ag) with increasing xMn concentration gives strong evidence for the presence of Mn2+ ions in sulfur vacancies (VS) in the Sb2S3 unit cell. Optical absorption and photoluminescence (PL) spectroscopy measurements for xMn-doped Sb2S3 NCs show the subtle tunable redshift of the band gap and excitonic recombination in the green-red region, with increasing x concentration. PL confirms that dopant Mn2+ ions fill VS2 that are dominant in Sb2S3. Therefore, the position of the energy states after the increasing concentration of Mn2+ dopant ions gives rise to insight into luminescence for future research scenarios and applications involving sustainable DMS NCs.