Spectroscopic Properties Of Nd3 Research Articles

Optical spectroscopy of Nd3+-doped cadmium-rich borate glasses for near-infrared laser applications

AbstractThe structural and spectroscopic properties of Nd3+-activated cadmium-rich borate (inverted) glasses are analyzed for near-infrared laser applications. The evaluation of the optimal glass-emitting sample by the Judd–Ofelt (JO) theory revealed JO parameter values of 4.56 × 10–20 cm2 (Ω2), 2.56 × 10–20 cm2 (Ω4), and 3.84 × 10–20 cm2 (Ω6). The Ω2 value, along with the experimental oscillator strength, suggested that the cadmium-rich borate glass could provide a more asymmetrical Nd3+ environment than other borate glasses like lithium-strontium-zinc, sodium-calcium, and lithium-lead-aluminum. In addition, the quality spectroscopy factor (χ = Ω4/Ω6) of 0.67 suggested that the 4F3/2 → 4I11/2 emission could be more suitable for laser applications. The stimulated emission cross-section (σp), theoretical quantum yield (ηQ), gain bandwidth (σp × Δλem), and optical gain (σp × τrad) laser parameters were close to those reported in sodium-calcium-borate, zinc-aluminum-barium-borate, and bismuth-borate glasses, while the non-radiative rate (WNR) and emission intensity saturation (IS) resulted to be lower. The emission spectra, under 808 nm laser excitation, displayed the featured neodymium 4F3/2 → 4I9/2,11/2,13/2 transitions, being the 4F3/2 → 4I11/2 (1058 nm) transition the more dominant one, in agreement with the χ parameter value. Nd3+ contents higher than 1.4 mol% led to emission quenching due to the increment of the cross-relaxation and/or energy migration rate. Such processes, according to the Inokuti–Hirayama model, were mainly mediated by electric dipole–dipole interactions within Nd–Nd clusters.

Crystal growth and spectroscopic properties of Nd3+ -doped SrB4O7 single crystal

Single crystal of Nd3+ -doped SrB4O7 (SBO) has been successfully grown by the Czochralski method. The spectroscopic properties were investigated and spectral parameters were calculated based on the Judd–Ofelt theory. The results suggest that the Nd:SBO crystal may have great potential as laser crystal, and through self-frequency doubling, it is expected to achieve the frequency conversion of the characteristic output of Nd3+ in the near infrared to obtain a visible laser.

Influence of Ultrahigh Dilution Treatment of the Charge on the Growth and Spectroscopic Properties of Nd:MgMoO4 Potential Laser Crystal

The influence of the charge treatment by ultrahigh dilution (UHD) technology on oxide single crystals grown by the Czochralski technique was studied for monoclinic MgMoO4 crystals doped by 1 at. % of Nd3+ ions. The series of 10 Nd:MgMoO4 crystals was grown from the charges that were subjected to UHD treatment, as well as from the charges treated with two types of control or with no special treatment at all. The grown crystals were studied by X-ray powder diffraction analysis, inductively coupled plasma atomic emission spectroscopy, mass-spectrometry, optical absorption, emission spectroscopy and luminescence kinetic analysis. We found that: (i) wetting of MgO + MoO3 mixture by a water-ethanol solution before calcining leads to some enrichment of the mixture with MoO3, whereas the wetting of the charge after the calcining leads to some enrichment of it with MgO; (ii) congruent melting composition of MgMoO4 crystal is in the field of some MoO3 excess; (iii) the solid-phase solubility of the excess MoO3 in MgMoO4 probably does not depend on temperature, whereas the solid-phase solubility of the excess MgO in MgMoO4 crystal depends on temperature. We suggest that the corresponding solidus line passes through the range of retrograde solubility; (iv) the crystals grown within this range are characterized by the enhanced Nd3+ segregation coefficient between the crystal and the melt (approximately 0.006 versus 0.004); (v) unit cell parameters of MgMoO4 crystal with the excess of MoO3 are larger than those of the crystal of the stoichiometric composition and of the crystal with the excess of MgO; (vi) the shapes of the optical absorption and luminescence spectra of Nd:MgMoO4 crystal do not depend on the charge treatment; (vii) luminescence decay kinetics are single-exponential for all the studied crystals, the luminescence decay time being different for the crystals grown from the charges that underwent different types of treatment; (viii) the luminescence intensity of Nd:MgMoO4 crystal grown from the charge that underwent UHD treatment before calcining (solid-phase synthesis) is reduced by an order of magnitude in comparison with the other studied crystals.

Effect of mixed alkali ions on the structural and spectroscopic properties of Nd3+ doped silicate glasses

In the present work the effect of alkali ions (Li, Na, K) and the combination of them on structural and spectroscopic properties of Nd3+ doped silicate glasses were systematically investigated. Results from infrared and Raman spectroscopy, as well as density and refractive index, were used to investigate the effect on the structural properties of the silicate glasses. Absorption and emission spectra of the glass samples were measured in the UV-VIS and NIR ranges. Relatively large, stimulated emission cross-section at 1.06 μm was obtained for samples containing a combination of alkali ions, especially with potassium. Moreover, the splitting induced by the Stark effect on the hypersensitive transition of Nd3+,4I9/2 → 4G5/2, 2G7/2 was larger for the samples containing potassium, probably due to its larger ionic size. Judd-Ofelt theory was applied to evaluate the phenomenological intensity parameters Ω2, Ω4, Ω6, transition probabilities, radiative lifetimes and branching ratios related to Nd3+ ions, calculated from optical absorption and luminescence spectra and the results were compared to the values obtained for different Nd-doped glasses reported in the literature.

Spectroscopic and magneto-optical properties of novel bifunctional Nd,Er:CeF3 crystal

In this study, we report a successful Bridgman growth of Nd3+ and Er3+ co-doped CeF3 (Nd,Er:CeF3) single crystal with a size of Ø25 mm × 30 mm. The absorption and fluorescence characteristics of the Nd,Er:CeF3 crystal were studied systematically. The results show that the fluorescence emission peaks were positioned at 547, 669, 1062.6, and 1542.6 nm, respectively. The fluorescence lifetimes centered at 1062.6 and 1542.6 nm for Nd3+ and Er3+ were 0.313 and 1.12 ms, respectively. Meanwhile, the spectroscopic properties of Nd,Er:CeF3 crystals were investigated based on the Judd–Ofelt theory. Notably, the magneto-optical performance of the Nd,Er:CeF3 crystal was investigated for the first time. The Verdet constants of the Nd,Er:CeF3 crystal at 532, 632.8, 1064, and 1310 nm are 220.3, 142.4, 40.7, and 23.1 rad T−1 m−1, respectively, which are significantly higher than those of undoped CeF3 and traditional Tb3Ga5O12. The results show that Nd,Er:CeF3 is a bifunctional crystal with potential applications in laser and magneto-optical fields.

STUDY OF PHYSICAL AND LUMINESCENCE PROPERTIES ND IONS - DOPED TE-W-PB GLASSES

New Te-W-Pb oxide base glasses codoped with neodymium oxide have been prepared by traditional melt and quench method. X-ray diffraction (XRD) is done for the confirmation of glassy structure of samples. Differential scanning calorimetry (DSC) gives the information of thermal properties of prepared glasses. Raman spectra are studied to get structural information of glasses. The spectroscopic properties of Nd3+ were examined. Infrared emission at 878, 1062, and 1339 nm were seen during stimulation at 804 nm using a diode laser.

Effect of Gd3+/Nd3+- dual doped borate glasses on the physical and spectroscopic properties for the NIR emission at 1.069 µm

Near-infrared luminescence properties of dual doped Gd3+/Nd3+-incorporated glasses were manufactured using the melt-quenching technique and characterized by several techniques. The modification in glass structure may be seen in the differences in density, molar volume, and refractive index that occur when the amount of lanthanide oxide in the glass increases. The spectroscopic properties of Nd3+ in these glasses are quite well understood, and the observed optical characteristics may be used to process and eventually determine laser properties. According to the results of XANES, the Nd oxidation state remains the predominant peak for Nd3+ in all of the samples. The transition from 4I9/2 to 4G5/2 +2G7/2 is important for the strongest band in the absorption spectra, which can be seen at 584 nm. The luminescence spectra show peaks caused by 4F3/2→4IJ (J=11/2, 13/2) at three excitation wavelengths of 526, 574 and 805 nm. After the processing, we created glass samples for the study of photoluminescence with various amounts of Nd2O3 incorporated into the best host, 25Li2O-5Al2O3-2.5Gd2O3-(67.5-X)B2O3-XNd2O3. Based on luminescence intensity, it is determined that 1.0 mol% of Nd2O3 is the concentration quenching in the studied glasses. The 4F3/2 →4I11/2 transition at 1069 nm, excited by 526, 578 and 803 nm, has the highest emission intensity. The combined findings of the glasses demonstrate that near-infrared luminescence may be successfully used with them. All of the analysis shows that the dual doped Gd3+/Nd3+ borate glass would be a potential solid-state laser candidate.

Study on influence of modifiers on structural and spectroscopic properties of Nd3+ doped different lithium tetra borate glasses

Different multi-component (Li, Na, Ca, Ba, LiNa, BaCa) borate glasses doped with 1 mol% of Nd3+ ions were prepared by the melt-quenching method. The structural information was carried out by PXRD, FTIR and 11B MAS-NMR characterizations. Based on Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC), thermal stability has been taken care for the glass samples which are mentioned at present work. From PXRD, it is clearly observed that the prepared glass samples are amorphous in nature. The FTIR spectra were examined to determine if the borate glasses contained BO3 or BO4 functional groups.11B MAS NMR gives structural presentation of BO3 and BO4 groups and boron-oxygen coordination number. The evaluation of Judd-Ofelt parameters, Ω λ (λ = 2, 4, 6), and spectroscopic quality factors (χ) were conducted based on the optical absorption spectra and spectral intensities. The present study involves an analysis of the transition probabilities (A) and branching ratios (β) of specific transitions of Nd3+ ion doped in various glasses, utilizing the Judd-Ofelt intensity parameters. The emission spectra of the glass samples were recorded with 808 nm excitation, it shows three peaks at 881, 1050 and 1332 nm. Theoretical analysis was conducted on the luminescence properties of borate glasses, and various radiative properties were also investigated. From the luminescent properties of Nd3+ doped different lithium tetraborate glasses, it is concluded that LiBiNaTNd and LiBiBaCaTNd glasses are promising gain materials for 1.05 μm fiber laser applications.

Evaluation of the Structural, Near-Infrared Luminescence, and Radioluminescence Properties of Nd3+ Activated TTB-Lead Metatantalate Phosphors

The study reports the structural and spectroscopic properties of Nd3+ doped lead metatantalate phosphor series fabricated by conventional solid state method. XRD results of the PbTa2O6 phase confirm the tungsten bronze symmetry and single-phase structure between 0.5 and 10 mol% Nd3+ concentrations. The lead decrease in the structure can be associated with maintaining the charge balance and single phase due to evaporation during sintering. In SEM micrographs, the grains exhibited shapeless morphology, and the grain sizes varied from 0.5 to 7 m. In EDS results, the increase of Ta/Pb ratio in grain surfaces indicated some lead evaporation, as reported in previous studies. The absorption spectrum of PbTa2O6 host peaked around 275-280 nm, and the band gap was found to be 3.7±0.2 eV. The absorptions of Nd3+ doped phophors shifted the high wavelenght or the low band gap, where the band gaps were found between 3.1±0.2 and 3.3±0.2 eV. The PL emissions of the phosphors in near-inrared region were observed with the transitions of 4F3/2→4I9/2 (at 875 nm) and 4F3/2→4I11/2 (at 1060 nm) of Nd3+. The RL emissions or X-ray excited luminescence were monitored with the transitions of 4F3/2→4I9/2 (at 875 nm), 4F3/2→4I11/2 (at 1065 nm) in the infrared region, and the transitions of 2F(2)5/2→4F9/2, 2F(2)5/2→2H(2)11/2, 2F(2)5/2→4G5/2, 2F(2)5/2→4G7/2, 2F(2)5/2→4G9/2 in the visible region corresponding to at around 430, 455, 490, 525, and 570 nm, respectively. PL and RL emissions of the phosphors exhibited the decreasing emission intensity over 5 mol% due to the concentration quenching which may be associated with cross-relaxing mechanism. In the PL and RL spectral profiles, the similarity of splitting levels was attributed to the similarity of the local symmetry of the ligand ions surrounding the Nd3+ ion. The CIE coordinates obtained using RL emissions were found close to the blue region due to visible region transitions.

Effect of silica-alumina co-introduction on structure as well as physical and spectroscopic properties of Nd3+-doped potassium phosphate glass

The effect of silica-alumina co-introduction on physical and spectroscopic properties of Nd3+-doped potassium phosphate glass was investigated. The Raman and X-ray photoelectron spectroscopy (XPS), physical parameters as well as spectroscopic characteristics were determined and analyzed in detail. Q2 units gradually increase while Q1 units have the opposite trend with the increase of SiO2/Al2O3 ratios. Meanwhile the total number of [AlO6] octahedrons and [AlO4] tetrahedrons continue to decrease with [AlO6]/ [AlO6]+ [AlO4] ratio keeping rise. As a result, the increase of more symmetrical bridge oxygen bonds and more ionic Si-O bonds lead to more centrosymmetric and stronger ionicity of Nd3+ ion coordination environment. The physical and spectroscopic properties of glasses benefit from silica-alumina co-introduction. When SiO2/Al2O3 ratio was 1.8, the glass showed a high emission cross-section of 3.05 × 10−20 cm2, a high optical gain parameter of 10.8 × 10−24 cm2s, together with wider gain bandwidth parameter of 7.61 × 10−26 cm3.

Influence of ionic liquid and oleic acid assisted methods on the spectroscopic properties of Nd3+-doped GdPO4 nano-particles

TEM analysis revealed the most homogenous nano-material obtained via an ionic liquid microwave-assisted method. The energy level diagram for Nd3+ ions in GdPO4 was proposed for high-quality materials obtained from the ionic liquid precursor.

Statistical Structure Gene Modeling of Alkali to Spectroscopic Properties of Nd∶Phosphate Glass

Statistical Structure Gene Modeling of Alkali to Spectroscopic Properties of Nd∶Phosphate Glass

Quantitatively predicting the optical and spectroscopic properties of Nd3+‐doped laser glasses

AbstractPredicting the properties of glass based on compositional and structural information is a fundamental issue with enormous practical and industrial significance for the study of laser glass. Here we address this problem and demonstrate the application of phase diagram method in predicting the spectroscopic properties of Nd3+‐doped binary and ternary silicate, binary phosphate, and borate laser glasses from their initial congruently melting compounds. In particular, spectroscopic properties, such as effective linewidth (Δλeff) and fluorescence branching ratio (β) can be precisely predicted in all glass systems with an error less than 5%. Furthermore, a composition–structure–property database of Nd3+‐doped ternary silicate glass system is established and preliminarily applied to the composition design and explanation of commercial glass. This study provides interpretable predictions of the optical and spectroscopic properties for Nd3+‐doped laser glasses.

Spectroscopic properties of Nd3+-doped boro-bismuth glasses for laser applications

Trivalent neodymium (Nd3+)-doped boro-bismuth glasses have been prepared adopting the high temperature melt and quick quenching procedure and investigated their physical and optical characteristics. Physical properties and their relationship with the composition are demonstrated. Judd-Ofelt parameters have been derived using absorption spectra of Nd3+ ions embedded boro-bismuth glasses and are taken to estimate radiative parameters of the fluorescent states of Nd3+ ions. The calculated radiative properties, experimental quantities derived from emission spectra and decay curves of the 4F3/2 state provide comprehensive optical properties of the glasses besides their emission capability for the laser activity near 1.06 μm.

Nd3+ doped titanate-germanate glasses for near-IR laser applications

In current work, spectroscopic properties of Nd3+ ions in titanate-germanate glasses have been studied for near-IR luminescence and laser applications. Near-IR luminescence at 1.06 µm due to 4F3/2 → 4I11/2 laser transition of Nd3+ ions has been examined in the function of TiO2 concentration. Based on theoretical calculations and experimental investigations, several spectroscopic and laser parameters for Nd3+ ions in titanate-germanate glasses were determined and compared to the previous results published for similar glass systems. Our systematic studies indicate that Nd3+ doped glass with molar ratio GeO2:TiO2 = 2:1 presents excellent near-IR luminescence properties and could be successfully applied to laser technology.

Development of neodymium (III) ions doped sodium fluoro-borate glass composite materials and study of the laser emission

Neodymium (III) ions doped sodium fluoro-borate (BCNF) glass materials have been prepared by the melt quenching method and Fourier transform infrared (FTIR) method was intended for the identification of the functional groups present in the BCNF host glass. X-ray diffraction (XRD) analysis is used for the study of structural details of the prepared glass composite materials. In order to study the spectroscopic properties of fabricated glasses, absorption, emission and decay measurements has been performed. Additionally, the spectroscopic properties of Nd3+ ions were analyzed using Judd-Ofelt theory. UV–Vis and Near-IR absorption spectra of glass composite samples reveal eleven significant peaks. Under the excitation of 808 nm laser diode, three near-IR emission bands are at around 876 nm, 1058 nm and 1331 nm from 4F3/2 → 4I9/2, 4I11/2 and 4I13/2 radiative transitions, respectively, were observed in the Nd3+ ions doped glass composite material. The lifetimes of this transition has been experimentally determined through decay profile studies. For all Nd3+ ion concentrations, the decay time curves of the 4F3/2 level were essentially single exponential.

Dehydroxylation processing and lasing properties of a Nd alumino-phosphate glass

In this work, we have studied the preparation and properties of an alumino-phosphate glass with composition 13Na2O-13K2O-16BaO-4Al2O3-54P2O5 (mol%). The first part of the work deals with the study of the processing conditions of the dehydroxylation of the phosphate glass, which was performed by remelting under N2 flow using graphite crucibles. Glass samples from 5 to 50 g and Nd2O3 doped were submitted to dehydroxylation and the influence of temperature, time, mass of glass and viscosity were correlated with the content of water in the glasses through the coefficient of absorption of OH ions. The network structure of the glasses was also determined by means of 31P and 27Al 1D/2D nuclear magnetic resonance and the local environment of Nd3+ ions was probed by electron paramagnetic resonance. The optimized conditions of processing were then used to obtain a dehydroxylated glass with a 2.5 wt% Nd2O3 whose spectroscopic and laser emission properties were studied. The spectroscopic properties of Nd3+ ions which include, Judd-Ofelt calculation, stimulated emission cross-section of the laser transition, lifetime, and quantum efficiency are presented. Site-selective laser spectroscopy and stimulated emission obtained under selective wavelength pumping along the 4I9/2→4F5/2 absorption band were performed to determine the distribution of crystal field in which the rare earth is located, together with its influence in the pump wavelength dependence of the spontaneous and laser emissions of Nd3+ in this glass matrix.

Structure, thermal and spectroscopic properties of Nd:YAlO3 perovskite crystal between 77 to 300 K for the design of cryogenic cooled solid state laser

The solid-state lasers provide an attractive approach to enhance the laser performance benefitting from significant improvements in both thermo-optic and spectroscopic properties of the gain mediums under cryogenic temperature. We have systematically investigated the structure, thermal and spectral properties of Nd:YAlO3 (Nd:YAP) in the temperature range of 77–300 K. We found that the thermal expansion coefficient of a-cut Nd:YAP crystal is about zero around 180 K. The zero-thermal-expansion could lead to negligible thermal effect and suppress optical distortion in high average power lasers, which provides great help for high power and high beam quality laser generation. The increase in thermal conductivity and reduced thermal expansion at cryogenic temperature lead to thermal shock resistance parameter significantly larger than that at room temperature. Furthermore, the detailed thermal and spectral properties of Nd:YAP crystal in the temperature range across 77–300 K were determined. All results of the Nd:YAP crystal, in particular, the emergence of zero-thermal-expansion, provide important information for the design of cryogenic cooled high-power lasers.

Investigation of optical and spectroscopic properties of Nd co-doped Yb:YVO4 single crystals grown by OFZ method

Nd (0.8 at.%) co-doped Yb (0.8 and 3.0 at.%):YVO4 single crystals were grown by optical floating zone technique for the first time to the best of our knowledge. The absorption spectra revealed strong absorption for π-polarization (E||c) than the σ-polarization (E⊥c) for both the Yb concentrations due to anisotropy of the crystal. The estimated effective Judd-Ofelt parameters are 11.8675 × 10−20, 5.1577 × 10−20 and 7.3755 × 10−20 cm−2. Spectroscopic quality factor of Nd co-doped Yb:YVO4 are 0.70. which is lower than that of Nd (1.0 at.%) doped YVO4 (0.97), which indicates the energy transfer from Nd3+ ion to Yb3+ ion inside the host matrix. The estimated emission cross-section of 4F3/2 → 4I11/2 Nd transition with an excitation at 808 nm for both the concentrations of Yb is ∼4.0 × 10−19 cm2 which is almost same as estimated by Bhaumik et al. (2014) [21] for Nd:YVO4. Hence emission cross-section of 4F3/2 → 4I11/2 Nd transition is not effected by Yb co-doping. Also the PL intensity of Yb at 1010 nm enhances with Yb co-doping for same Nd (0.8 at.%) this is because the Nd3+ ion effectively excites the Yb3+ ion in upper state. Therefore Nd3+ ion acts as excellent sensitizer for Yb:YVO4 laser gain medium and make efficient pumping in the gain medium.

High-Efficiency Nd3+-Doped Phosphate Fiber Laser at 880 nm

Spectroscopic properties of Nd3+-doped phosphate glass for three-level laser were investigated for the first time. A 60 nm blue-shift of the three-level transition fluorescence spectrum was achieved by changing the host material from traditional silica glass to phosphate glass. An 880-nm all-fiber laser with a world-record slope efficiency of 42.8% was demonstrated with 25-cm-long 0.25-wt.% Nd3+-doped phosphate fiber. Our research shows that Nd3+-doped phosphate glass is a high-efficiency material for laser operation below 900 nm.