Luminescence Properties Of Nd3 Research Articles

Structural, vibrational and luminescence properties of Nd3+ ions in new Ca4Ln3Nb5O21 (Ln = La0.99Nd0.01, Nd, Gd0.99Nd0.01) niobate – Prospective laser materials

Research on the phase equilibria in one of the cross-sections of a CaO–Nd2O3–Nb2O5 ternary oxide system, i.e. the Ca2Nb2O7–Nd3NbO7 binary system, has shown the existence of a new solid solution with the general formula (Ca2Nb2)2xNd3NbO14x+7 (0 < x < 1) and a homogeneity range between Nd3NbO7 and Ca4Nd3Nb5O21 end-members. The dependence of the powder XRD patterns, as well as IR and Raman, emission and excitation spectra and luminescence decay times on mixture composition has been reported. XRD and spectroscopic studies show a continuous change of the substrates’ interaction within the existence limit of a new solid solution. Significant improvement of the luminescence properties was obtained by dilution of the optically active Nd3+ ions by gadolinium and lanthanum in the Ca4Nd3Nb5O21 end-member of the new solid solution. The spectroscopic measurements were used to propose the depopulation mechanism of the Nd3+ electron excited states in the studied materials. The optical band gaps of Ca2Nb2O7, Ca4Nd3Nb5O21 and Nd3NbO7 were calculated using Tauc plots.

Growth and luminescence properties of Nd,Cr:YSAG crystal

ABSTRACT In this study, 0.5 at% Cr3+ and 1 at% Nd3+ co-doped YSAG (Nd,Cr:YSAG) single crystal was grown by the Czochralski technique. The crystal structure is characterised with X-ray diffraction method. Compared with the absorption of Nd:YSAG crystal, two broad and intense absorption bands are observed in visible region of Nd,Cr:YSAG crystal, which are corresponding to the transitions of Cr3+ from ground state 4A2 to excited states 4T1 and 4T2, respectively. Using visible lights excitation (459 nm and 589 nm), the emission intensity of Nd,Cr:YSAG crystal is much stronger than that of Nd:YSAG crystal. The energy transfer mechanism from Cr3+ to Nd3+ ions in YSAG crystal is analysed. All the results indicate that Nd,Cr:YSAG is a promising high efficient 1 μm laser crystal suitable for solar or flash lamp pumping.

Luminescence Properties of Nd3+‐Doped AlF3‐Based Fluoride Glass in the Vacuum Ultraviolet Region

The development and characterization of the optical properties of a neodymium(III)‐doped 42.75AlF3–33.25CaF2–19BaF2–5YF3 (Nd3+‐doped BCA‐5Y) glass in the vacuum ultraviolet (VUV) region are reported. Photoluminescence peaks at 180 and 227 nm are observed upon excitation with the 157 nm emission of a F2 laser. The dominant 180 nm emission peak is assigned to the 4f25d–4f3 (4I9/2 level) transition in Nd3+. This emission peak exhibits a fast, single exponential luminescence with a 16 ns decay time. The strong luminescence intensity and the fast decay time allude to its prospects for scintillator applications.

Highly efficient up-conversion in Nd:Y2O3 transparent ceramics

Up-conversion (UC) luminescence properties of Nd:Y2O3transparent ceramics are investigated. It is shown that, under a laser excitation of 808 nm, the samples exhibit significant UC emission. With an increase in the Nd3+ concentration, the intensity of green emission decreases, while the intensity of red emission first increases and then decreases. In particular, both green and red UC emissions are found to be two-photon processes, but with different quantum transition mechanisms. In addition, the dependence of UC emission intensity on the pumping power is studied. Our studies indicate that Nd:Y2O3 transparent ceramics are promising candidates as short-wavelength UC laser material.

Control of defects and their luminescence properties in Nd:YAG crystals by laser irradiation

This paper presents luminescence properties of Nd:YAG crystal defects including oxygen vacancy, O− hole center, F and F+ centers before and after laser pre-irradiation. These Nd:YAG crystal defects have the photoluminescence emission peaks in the range of ∼350–500 nm in the UV–Vis region of the spectrum. Under different laser parameters, irradiated crystals show different photoluminescence properties. The results show that laser irradiation can control photoluminescence properties of the Nd:YAG crystal samples. The present work can give a new approach to modify optical properties of Nd:YAG crystals to be used in a wide variety of solid-state laser engineering.

Effect of Al co-doping on the luminescence properties of Nd3+-doped TiO2 thin films

Co-doping Aluminium (Al) with neodymium (Nd) is shown to have a sensitizing effect on the rare earth luminescence in thin film titanium dioxide (TiO2) host materials. Whilst the Al co-doping has the effect of quenching the direct (resonantly) excited, steady state photoluminescence from Nd3+ emitting centers, for indirect (non-resonant) excitation, the emission is enhanced with increasing Al. Time-resolved PL measurements reveal a decrease in both the excitation/de-excitation rates (increases in lifetime) with increasing Al co-doping, confirming the indirect nature of excitation and implying a suppression of non-radiative de-excitation of the Nd3+ centers in TiO2. Suppression of non-radiative processes by Al is considered to be the result of reduced rare earth clustering, which is known to promote de-excitation via energy migration and thus has important implications for improved efficiency infra-red LED materials.

Quantitative prediction of the structure and luminescence properties of Nd3+ doped borate laser glasses

AbstractAlthough great advance has been made in glass science, predicting luminescence properties of laser glass poses a significant challenge for scientists due to the complex relationship between the composition, structure, and properties of the rare earth ions doped laser glasses. The development of high‐performance laser glass usually relies on intuition and trial‐and‐error. Recently, with the proposal of the materials genome engineering, the “glass genome” has also attracted much attention. Here, the structure of the Nd3+ doped B2O3‐Li2O laser glasses was analyzed using Fourier transform infrared spectra and nuclear magnetic resonance, revealing that the glass contains similar glass‐forming ion‐centered coordination polyhedron structure groups to the neighbor congruent glassy compounds. The structure and properties of glass largely depend on the neighbor congruent glassy compounds. Therefore, the structure and luminescence properties of Nd3+ doped B2O3‐Li2O and B2O3‐MgO‐Li2O laser glasses can be quantitatively predicted via the neighbor congruent glassy compounds. The predictive values are in good agreement with the experimental data, which indicates that our approach is an effective way to predict the structure and luminescence properties of Nd3+ doped borate laser glasses.

Relationship investigation of structure and properties of Nd3+: Ga2O3-Al2O3-PbO-CaO via Raman, infrared, NMR and EPR spectroscopy

A detailed study structure and luminescence properties of Nd3+: Ga2O3-Al2O3-PbO-CaO laser glasses was conducted. The network structure was mainly dominated by Al (IV) or Ga (IV). With the increase of the Al2O3 content, the Al (IV) content increases, whereas the Ga (IV) content decreases. Hyperfine sublevel correlation (HYSCORE) spectra reveal 27Al and 207Pb weak hyperfine coupling, which indicates that these nuclei are in the second- or higher-order Nd3+ coordination sphere. No 69Ga or 71Ga signals can be detected in the three-pulse electron spin echo envelope modulation (3P-ESEEM) and HYSCORE spectra. For germanate glass, the local environment of the Nd3+ ions is characterized by the Pb ligand, for aluminum gallium glasses, the Nd3+ ions are surrounded by Al3+ and Pb2+ ions, and for aluminum glass, Nd3+ ions are mainly surrounded by 27Al cations. The change in the structure and in the local environment of Nd3+ ions results in a change in the luminescence properties of glasses.

The effect of Gd3+ ions on fabrication and luminescence properties of Nd3+-doped (Ca1-xGdx)F2+x transparent ceramics

Nd:(Ca1-xGdx)F2+x (x = 0.01–0.1) transparent ceramics were fabricated by hot-pressing the co-precipitated synthetic nanopowders in vacuum. The as-fabricated Nd:(Ca1-xGdx)F2+x transparent ceramics exhibit nearly pore-free and uniform microstructure, the in-line transmittance of all samples is beyond 86% at 1064 nm. The effect of Gd3+ ions on the transparency and grain size of Nd:(Ca1-xGdx)F2+x transparent ceramics has been demonstrated. The dependence of emission intensity and lifetime on Gd3+ concentration for Nd:(Ca1-xGdx)F2+x transparent ceramics is investigated and discussed. The introducing of Gd3+ is found to increase emission intensity and lifetime dramatically. The fitting results of fluorescence decay curves show the lifetime of 1 at.% Nd:(Ca0.9Gd0.1)F2.1 transparent ceramic is to be 373.80 μs which is greatly larger than that of 1 at.% Nd:CaF2 transparent ceramic. The spectroscopic parameters of Nd:(Ca1-xGdx)F2+x transparent ceramics and other Nd3+-doped optical materials have been compared and discussed.

Optical and structural properties of Nd:MgO:LiNbO3 crystal irradiated by 2.8-MeV He ions

We report the optical and structural properties of helium-implanted optical waveguides in Nd:MgO:LiNbO3 laser crystals. The prism-coupling method is used to investigate the dark-mode properties at the wavelength of 632.8 nm. The spontaneous generation of ultraviolet, blue, red, and near-infrared fluorescence emissions is demonstrated under excitation with an 808-nm laser diode. The effects of ion irradiation on the structural properties are characterized using the high-resolution X-ray diffraction technique. The results show that the initial luminescence properties of Nd:MgO:LiNbO3 crystals are slightly modified by irradiation with 2.8 MeV He ions at fluences of 1.5 × 1016 ions/cm2 at room temperature.

Efficient 2 µm emission in Nd3+/Ho3+ co-doped silicate-germanate glass pumped by common 808 nm LD

Nd3+/Ho3+ co-doped silicate-germanate glass has been synthesized by high temperature melt-quenching method. Near infrared emission centered at 2µm has been successfully obtained by incorporating Nd3+ and Ho3+ in present glass. The Judd-Ofelt intensity parameters Ωt (t=2, 4, 6), and radiative properties of Ho3+ were calculated and discussed by using the Judd-Ofelt theory. The energy transfer processes and luminescence properties of Nd3+/Ho3+ co-doped glasses were analyzed pumped by a conventional 808nm laser diode. Desirable spectroscopic characteristics indicates that Nd3+/Ho3+ co-doped silicate-germanate glass might be a good alternative matrix for 2µm band mid-infrared laser.

Effect of P2O5 addition on structural and luminescence properties of Nd3+-doped tellurite glasses

Effect of P2O5 addition on spectroscopic properties of trivalent neodymium (Nd3+)-doped tellurite glasses was studied through Raman, absorption, emission and decay measurements. Raman spectra (350–1250 cm−1) of the Nd3+-doped tellurite glasses with various P2O5 concentrations, were obtained upon 514 nm Ar+ laser excitation and found that bandwidth of the intense band increased with the addition of P2O5 from 0 to 20 mol%, indicating the transformation of TeO4 into TeO3+1 and TeO3 units. Judd-Ofelt intensity parameters and radiative properties of luminescent 4F3/2 level were evaluated using absorption spectra for all the glasses. Luminescence spectra were measured in the region 840–1500 nm under 806 nm diode laser excitation. The decay curves for the 4F3/2 level of Nd3+ ion were recorded under 806 nm diode laser excitation by registering the emission at 1058 nm and the lifetime has been found to increase from 188 μs to 249 μs when P2O5 concentration increased from 0 to 20 mol%. The figure of merit and quantum efficiency were evaluated and compared to the other reported Nd3+-doped glasses. The results indicate that the investigated phospho-tellurite glasses could be useful as laser gain media around 1060 nm.

Luminescence Properties of Nd$_{2}$O$_{3}$-doped Gadolinium-Borate Glass Scintillators

Luminescence Properties of Nd$_{2}$O$_{3}$-doped Gadolinium-Borate Glass Scintillators

Study on luminescence properties of Nd3+–La3+ and Nd3+–Sc3+ codoped M′-LuTaO4 phosphors

Nd3+ doped M′-LuTaO4 phosphor, with high density (9.8g/cm3) and relatively fast decay time (261ns), is a potential heavy scintillator. In this work, Nd:LuTaO4 is codoped with La3+ or Sc3+ ion and its structure and luminescent properties as a function of their concentration are studied. The structural parameters are obtained by Rietveld refinement. The strongest emission peak is located at 419nm which corresponds to the 4D3/2→4I13/2 transition of Nd3+. The decay times of 4D3/2→4I13/2 transition in Nd/La:LuTaO4 and in Nd/Sc:LuTaO4 are much shorter than that in Nd:LuTaO4, which decrease to 211ns and 163ns, respectively. It is also found that the decay time of 4D3/2→4I13/2 transition in Nd/La:LuTaO4 increases with the increase of La content, and the decay time of 4D3/2→4I13/2 transition in Nd/Sc:LuTaO4 decreases with the increase of Sc content. Besides, the mechanism is discussed respectively.

Up- and Downconversion Luminescence Properties of Nd3+Ions Doped in Bi2O3–BaO–B2O3Glass System

Physical, optical, and luminescence properties of Nd3+ions in bismuth barium borate glass system were studied. The glasses prepared by a melt quenching method were doped at various Nd2O3concentrations in compositions (40-x)B2O3 : 40Bi2O3 : 20BaO : xNd2O3(wherex= 0.00, 0.50, 1.00, 1.50, 2.00, and 2.50 in mol%). Luminescence properties of the glasses were studied under two excitations of 585 and 750 nm for downconversion. From both excitations, the results show emission bands in NIR region corresponding to the transitions between4F3/2 → 4I9/2(900 nm),4F3/2 → 4I11/2(1,060 nm), and4F3/2 → 4I13/2(1,345 nm). The luminescence intensity obtained with 585 nm excitation was stronger than 750 nm, with the strongest NIR emission at 1,060 nm. The upconversion emission spectrum exhibits strong fluorescence bands in the UV region at 394 nm (λex=591 nm). The processes are associated with excited state absorption (ESA) from4F3/2level to4D3/2level and it is the radiative decay from the4D3/2to ground levels (4D3/2 → 4I13/2) which are responsible for the emission at 394 nm.

Effect of composition deviation on the microstructure and luminescence properties of Nd:YAG ceramics

Non-stoichiometric compositions lead to microstructures different from that of stoichiometric Nd:YAG. Nanograins of excess Al2O3 remain inside the Nd:YAG grains in Al2O3-excess ceramics, while Y-rich compounds recrystallize at the Nd:YAG grain boundaries in Y2O3-excess ceramics.

Luminescence properties of Nd3+ doped LiLuF4 single crystals with different dopant concentrations

Nd-doped LuLiF4 single crystalline scintillators with different Nd concentrations of 1%, 2%, 3%, and 4% were grown by the micro-pulling-down (μ-PD) method and that of Nd 1% were grown by the Czochralski method. There are some absorption bands due to Nd3+ 4f–4f transitions in the spectra and these lines correspond to the transitions from the ground state 4I9/2 to the excited states. In photo- and radio-luminescence spectra, Nd3+ 4f–4f transition peaks were observed. The photoluminescence decay time for 4D3/2→4I13/2 transition showed approximately 0.75μs and slow component. The highest light yield was estimated to be 700photon/MeV for LuLiF4:Nd2% crystal grown by the μ-PD method.

Luminescence properties of Nd3+ and Er3+ doped glasses in the VUV region

We report the vacuum ultraviolet (VUV) spectroscopy of APLF+Nd and APLF+Er glass, with composition 20Al(PO3)3-80LiF+1NdF3 and+1ErF3 (in mol%). APLF+Nd and APLF+Er have a dominant fluorescence peak at 185nm and 168nm with decay times of 4.5ns and 5.8ns, respectively. Fluorescence from APLF+Nd is attributed to 4f25d→4f3 transitions in neodymium (Nd) while fluorescence from APLF+Er is due to spin allowed transition in erbium (Er). This is the first report of VUV fluorescence from rare earth ions doped in glass hosts, which could provide the basis for mass production of VUV emitting materials. Our results also suggest the potential of using APLF+Nd and APLF+Er as neutron scintillators during inertial confinement fusion.

Laser-excited luminescence of trace Nd3+ impurity in LaBr3 revealed by Raman spectroscopy

Unexpected additional bands with obvious non-vibrational features were observed in Raman spectra of LaBr3. Extensive study was carried out to reveal the origin of these bands. Results indicate that the additional bands correspond to laser-excited luminescence of trace Nd3+ impurity unintentionally introduced from the La2O3 raw material, which was further confirmed by Raman spectra of specially prepared Nd3+-doped LaBr3 and LaOBr samples. The luminescence properties of Nd3+ in different matrix were compared and discussed. The ultrasensitivity of Raman spectroscopy in detecting trace luminescent lanthanide ions shows good potential for analytical applications.

Buried waveguides in Nd:YLF crystals obtained by femtosecond laser writing under double line approach

In this paper, we present buried waveguides fabricated by fs laser writing in Nd3+ doped YLF crystal under double line approach (Miura et al. in Appl. Phys. Lett. 71:3329–3331, 1997). The waveguides were made by focusing two consecutive optical breakdown tracks (OBT) separated by about 20 μm. To make the optimal OBT, we focused the fs-laser pulses 200 μm below surface at intensities above the OB threshold for the material and controlled the writing speed. The guiding structures were fabricated by using a Chirped Pulse Amplification (CPA) femtosecond (fs) laser system. We chose the optimal writing parameters in order to obtain suitable waveguides, using around 3 μJ energy and writing speed from 15 to 50 μm/s. After optically exploring the waveguides by end-fire coupling, the guiding structures showed good optical performance. Guiding index profiles were retrieved from modal analysis by using BeamProp (RSoft) commercial software. This spatial distribution of the index increment, taking into account a lower refractive barrier on the OBT region plus the compressed region between the tracks, was obtained correctly fitting profiles modes.Finally, optical spectroscopy measurements were also performed in the waveguides. The results showed that the luminescence properties of Nd3+ ions are preserved in the waveguides compared with the values obtained for bulk.