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Enhanced near-infrared emission in Yb3+-Cr3+ codoped KZnF3 glass ceramics excited by a solar simulator
摘要： Cr3+-Yb3+ codoped bulk glass-ceramics containing KZnF3 nanocrystals are fabricated by thermal treatment of cast glass samples and characterized by X-ray diffraction and transmission electron microscopy. The luminescent properties of the glass and glass ceramic are investigated from the measured photoluminescence spectra and fluorescent lifetime. The measurement results demonstrate that Cr3+ and Yb3+ ions are both predominantly hosted in the KZnF3 nanocrystals, and the energy absorbed by Cr3+ ions is efficiently transferred to Yb3+ ions when excited at 450 nm. Compared to the glass, the near-infrared emission in the Cr3+-Yb3+ codoped glass ceramics is significantly enhanced when the excitation wavelength lies in the range λ~400–800 nm of a solar simulator. Results indicate that the Cr3+-Yb3+ codoped KZnF3 glass ceramic provides a promising material for spectral conversion from visible sunlight to near-infrared emission and a novel gain material for solar pumped fiber laser.
关键词： Nanocrystal,Solar pumped,Glass ceramics,Near-infrared
更新于2025-09-23 15:23:52
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Up-conversion Luminescence Properties of Er3+/Yb3+ Co-Doped Oxyfluoride Glass Ceramic
摘要： Er3+/Yb3+ co-doped glass ceramic samples were prepared by melt-quenching method utilizing nominal composition 52SiO2-8Na2CO3-16Al2O3-33NaF-3LuF3-0.15Yb2O3-0.03Er2O3 (in mol%). The spectral characteristic was studied based on Judd-Ofelt theory. Spectrum intensity parameters Ωλ(λ=2,4,6) were calculated on the basis of the absorption spectrum. The theoretical and experimental oscillator strengths were calculated according to the spectrum intensity parameters, and the root mean square deviation (δrms) of glass ceramic sample was 4.28x10-6. The parameters such as transition probability, decay branching ratios and level lifetime of Er3+ were obtained. Lifetimes of metastable level 4I13/2 and 4I11/2 in as-prepared samples are respectively 11.64 and 13.61ms which are suitable for up-conversion intermediate levels. Decay branching ratio of 4I13/2→4I15/2 is nearly 100% in Er3+/Yb3+ co-doped oxyfluoride glass ceramic samples which can be used to produce 1543nm laser. Under the excitation of 980 nm diode laser, up-conversion luminescence is observed at the wavelength of 549nm and (653, 664) nm, corresponding to the radiative transitions of Er3+: 4S3/2→4I15/2 and 4F9/2→4I15/2, respectively. The numbers of absorbed photons in the transition process of Er3+/Yb3+ co-doped oxyfluoride glass ceramic samples are estimated at 1.99 and 2.06 respectively according to the relationship between the up-conversion transmitting power and the 980 nm LD laser power. It is determined that the transition process of Er3+/Yb3+ co-doped oxyfluoride glass ceramic samples is two-photon absorption process.
关键词： Glass ceramic,Two-photon absorption,Up-conversion,Judd-Ofelt theory
更新于2025-09-23 15:23:52
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Viscosity of chalcogenide glass-formers
摘要： Chalcogenide glass-formers are being used in a remarkable range of various optoelectronic, photonics, photoconducting, sensing and memory device applications. The knowledge of viscosity is essential for the processing of any glass-forming material, in particular for the fabrication of precise optical elements, which is the main application field of chalcogenide glasses. This work presents an extensive collection of all available viscosity data for chalcogenides, including the measurement methods. The Mauro–Yue–Ellison–Gupta–Allan (MYEGA), Arrhenius and VFT equations are used to fit the temperature dependences of viscosity. The viscosity glass transition temperatures, fragilities and apparent activation energies are calculated from these fits. Consequently, these parameters are discussed with regard to the compositional evolution of the respective chalcogenide systems.
关键词： glass transition,chalcogenide,viscous flow,fragility,Viscosity
更新于2025-09-23 15:23:52
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Effect of multi stage abrasive slurry jet polishing on surface generation in glass
摘要： The polishing process is used to produce a smooth surface with a required geometrical figure for the optical component. The abrasive slurry jet polishing process is one of the non-traditional polishing process, which is used to polish freeform optics with the nano-level surface finish. In the abrasive slurry jet polishing process, the saturation in surface roughness is observed with a jet exposure time or polishing time. Once the saturation limit is reached a further reduction in surface roughness without the modification of processing conditions and the size of the abrasive particles is not possible. Hence to achieve the required surface roughness a different polishing strategy has to be adapted. In this work, an attempt was carried out to yield a considerable reduction in surface roughness using a multistage polishing concept. In this concept, the impact angle, the traverse speed of the nozzle, the type and size of the abrasive particle were changed after the first stage of polishing. The surface generation has been studied by measuring the surface roughness at each stage of polishing, and the Scanning Electron Microscope (SEM) analyses have been done to understand the changes in surface texture, after polishing. From the experiments, the large size Al2O3 particle in the first stage of polishing and then small size Al2O3 particle in the remaining stages of polishing yields a considerable reduction in surface roughness. The combination of parameters with the type and size of the abrasive particles to be used to achieve the required surface characteristics were demonstrated. Thus, the multistage polishing concept can be floated as a viable strategy to achieve a high reduction in surface roughness on the optical component.
关键词： Abrasive,Particle size,Traverse speed,Slurry,Multistage Polishing,Glass
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Study of Oxyfluoride Glasses with Silver Molecular Clusters for Application in Sensoric and Optoelectronics
摘要： Temperature sensitivity of Oxyfluoride glasses with molecular silver clusters and samarium ions were studied. The experimental procedure for obtaining luminescence spectra at various temperatures is described. The perspective of using oxyfluoride glasses in fiber-optic temperature sensors is considered.
关键词： sensitive element,luminescence,Fiber-optical temperature sensor,oxyfluoride glass,spectrum,molecular clusters of silver
更新于2025-09-23 15:23:52
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Spectroscopic Properties of Er3+-Doped Particles-Containing Phosphate Glasses Fabricated Using the Direct Doping Method
摘要： The effect of the incorporation of Er2O3-doped particles on the structural and luminescence properties of phosphate glasses was investigated. A series of different Er2O3-doped TiO2, ZnO, and ZrO2 microparticles was synthesized using soft chemistry and then added into various phosphate glasses after the melting at a lower temperature than the melting temperature. The compositional, morphological, and structural analyses of the particles-containing glasses were performed using elemental mapping by field emission-scanning electron microscopy (FE-SEM) with energy dispersive x-ray spectrometry (EDS) and x-ray diffraction (XRD). Additionally, the luminescence spectra and the lifetime values were measured to study the influence of the particles incorporation on the spectroscopic properties of the glasses. From the spectroscopic properties of the glasses with the composition 50P2O5-40SrO-10Na2O, a large amount of the Er2O3-doped particles is thought to dissolve during the glass melting. Conversely, the particles were found to survive in glasses with a composition 90NaPO3-(10 ? x)Na2O-xNaF (with x = 0 and 10 mol %) due to their lower processing temperature, thus clearly showing that the direct doping method is a promising technique for the development of new active glasses.
关键词： oxyfluoride phosphate glass,direct particle doping,Er2O3-doped particles,Er3+ luminescence property,phosphate glass
更新于2025-09-23 15:22:29
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Influence of Sm2O3 Ion Concentration on Structural and Thermal Modification of TeO2-Na2O Glasses
摘要： The effect of Sm+3 ions concentration doped TeO2-Na2O glasses on structural and thermal parameters have been discussed. Glass samples with molar composition (80-x) TeO2-20Na2O-xSm2O3 glasses (x=0, 0.3, 0.6, 1, 1.2, 1.5) are prepared by melt quenching technique. Crystallization temperature (Tc), melting temperature (Tm) and glass transition temperature (Tg) are measured by using differential thermal analysis (DTA), it is found that the stability factor (ΔT) increases from (58.5-97.8) oC with the increasing of Sm2O3. The amorphous phase nature of the glass samples are observed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectrometer are applied to study the structural properties of the glass samples. Values of density (ρ), molar volume (VM), and ionic packing density (Vt) were calculated for each of the glass compositions. The effect of the Sm2O3 on the glass structure have been investigated by using FTIR and Raman spectroscopies, the FTIR spectra are characterized by a band of 637 cm-1 for the telluride glass, high frequency peak at 668 cm-1 presented by Raman spectra which indicates that these glasses network are basically consists of TeO4 and TeO3/TeO3+1 structural units. The spectra of Raman shows the presence of Sm-O bond, Na-O bond, Te-O-Te bridging configurations, vibrations of Te-O-Te bonds and stretching modes of non-bonding oxygen found on the TeO3/TeO3+1 structural unit.
关键词： Telluride glass,FTIR,Raman spectra,Rare Earth,Glass transition
更新于2025-09-23 15:22:29
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[IEEE 2017 5th International Conference on Instrumentation, Communications, Information Technology, and Biomedical Engineering (ICICI-BME) - Bandung, Indonesia (2017.11.6-2017.11.7)] 2017 5th International Conference on Instrumentation, Communications, Information Technology, and Biomedical Engineering (ICICI-BME) - Enhancement of Luminescence Light Yield of Ln <sup>3+</sup> Doped Glass By Oxyfluoride Glass Matrix
摘要： Glass is a good material which received attention for doping lanthanide ions. Glass doped Ln3+ ions can show luminescence, but not too strong light yield. It is well known that the host glass plays an important role in the enhancement. This paper has been described effect of Ln3+ ions (Sm3+, Eu3+ and Dy3+) doped oxyfluoride glass by comparing between oxide and oxyfluoride glasses. For the Sm3+ doped gadolinium calcium phosphate oxyfluoride glass, the highest emission peak was 598 nm under 401 nm excitation. While the emission light yield of oxyfluoride glass was higher than oxide glass due to the reduction of phonon and non-radiative losses. In case of Eu3+ doped oxyfluoride glass, the 612 nm emission under 394 nm excitation was observed. The light yield of oxyfluoride glass also was better than oxide glass. The Dy3+-doped phosphate oxide and oxyfluoride glasses were investigated. The luminescence light yield of oxyfluoride glass was more than oxide glass as well, owing to lower OH group of oxyfluoride glass, which can be confirmed by FTIR measurement. As described earlier, it concludes that the oxyfluoride glass is better than glass matrix when compared with oxide glass to enhance luminescence light yield for Ln3+ ions in glass matrix.
关键词： phonon energy,oxyfluoride glass,oxide glass,lanthanide ions
更新于2025-09-23 15:22:29
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Porosity Determination of Carbon and Glass Fibre Reinforced Polymers Using Phase-Contrast Imaging
摘要： This paper presents multi-modal image data of different fibre reinforced polymer samples acquired with a desktop Talbot-Lau grating interferometer (TLGI) X-ray computed tomography (XCT) system and compare the results with images acquired using conventional absorption-based XCT. Two different fibre reinforced polymer samples are investigated: (i) a carbon fibre reinforced polymer (CFRP) featuring a copper mesh embedded near the surface for lightning conduction and (ii) a short glass fibre reinforced polymer (GFRP) sample. The primary goal is the non-destructive detection of internal defects such as pores and the quantification of porosity. TLGI provides three imaging modalities including attenuation contrast (AC) due to absorption, differential phase contrast (DPC) due to refraction and dark-field contrast (DFC) due to scattering. In the case of the CFRP sample, DPC is less prone to metal streak artefacts improving the detection of pores that are located close to metal components. In addition, results of a metal artefact reduction (MAR) method, based on sinogram inpainting and an image fusion concept for AC, DPC and DPC, are presented. In the case of the GFRP sample, DPC between glass fibres and matrix is lower compared to AC while DPC shows an increased contrast between pores and its matrix. Porosity for the CFRP sample is determined by applying an appropriate global thresholding technique while an additional background removal is necessary for the GFRP sample.
关键词： Porosity,Carbon and glass fibre reinforced polymers,Talbot-Lau grating interferometer,X-ray computed tomography,Differential phase contrast
更新于2025-09-23 15:22:29
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Static and dynamic effective thickness in five-layered glass plates
摘要： In the last years, the effective thickness concept has been used to calculate deflections, stresses and modal parameters in laminated glass beams and plates, which consists of using a monolithic element with equivalent bending properties to a laminated element, i.e. the thickness of the equivalent monolithic model is time and temperature dependent because the interlayers show a viscoelastic behavior. Multi-layered laminated glass panels are those with at least three monolithic glass layers and two viscoelastic interlayers which are commonly used in floors, roofs and other applications where a high level of security is required. In this paper, a static deflection effective stiffness for a laminated glass plate consisting of three glass layers and two polymeric interlayers is derived. This static effective thickness is then extended to the frequency domain using the correspondence principle. The models are validated by static experimental tests and operational modal tests carried out on a rectangular multi-layered laminated glass plate pinned supported at the four corners.
关键词： B. Operational Modal Analysis,A. Laminated glass,C. Effective Thickness,D. Viscoelasticity
更新于2025-09-23 15:22:29