Transitions Of Nd3 Research Articles

Structural and optical properties of neodymium-doped lutetium fluoride thin films grown by pulsed laser deposition

Neodymium-doped lutetium fluoride (Nd3+:LuF3) thin films were successfully grown on MgF2 (001) substrates by pulsed laser deposition (PLD). It is void of cracks that are otherwise prevalent due to structural phase transitions in Nd3+:LuF3 during thin film deposition and bulk crystal growth. Cathodoluminescence (CL) spectra revealed multiple emission peaks, with a dominant peak in the vacuum ultraviolet (VUV) region at 179nm. This peak has a decay time of 6.7ns. The ability to grow high quality Nd3+-doped fluoride thin films would enable fabrication of VUV light-emitting devices that will enhance applications requiring efficient VUV light sources.

Solid state synthesis of SrAl2O4:Mn2+ co-doped with Nd3+ phosphor and its optical properties

The optical properties of alkaline earth aluminates doped with rare earth ions have received much attention in the last years and this is due to their chemical stability, long-afterglow (LAG) phosphorescence and high quantum efficiency. However, there is a lack of understanding about the nature of the rare earth ion trapping sites and the mechanisms which could activate and improve the emission centers in these materials. Therefore a new phosphor material composition, SrAl2O4:Mn2+, co-doped with Nd3+ was synthesized by a traditional solid-state reaction method. The influence of transition metal and rare earth doping on crystal structure and its luminescence properties have been investigated by using X-ray diffraction (XRD), Raman scattering, Photoluminescence (PL) and Radioluminescence (RL). Analysis of the related diffraction patterns has revealed a major phase characteristic of the monoclinic SrAl2O4 compound. Small amounts of the dopants MnCO3 and Nd2O3 have almost no effect on the crsytalline phase composition. Characteristic absorption bands from Nd3+ 4f–4f transitions in the spectra can be assigned to the transitions from the ground state 4I9/2 to the excited states. The luminescence of Mn2+ activated SrAl2O4 exhibits a broad green emission band from the synthesized phosphor particles under different excitation sources. This corresponds to the spin-forbidden transition of the d-orbital electron associated with the Mn2+ ion. In photo- and radio-luminescence spectra, Nd3+ 4f–4f transition peaks were observed. The emitted radiations for different luminescence techniques were dominated by 560, 870, 1057 and 1335nm peaks in the visible and NIR regions as a result of 4I9/2→4G7/2 and 4F3/2→4IJ (J=9/2, 11/2 and 13/2) transitions of Nd3+ ions, respectively. Multiple emission lines observed at each of these techniques are due to the crystal field splitting of the ground state of the emitting ions. The nature of the emission lines is discussed.

Nd3+-doped Ca3Ga2Ge3O12 garnet: A new optical pressure sensor

A pressure-induced shift of the emission spectrum corresponding to the near infrared 4F3/2 → 4I9/2 transition of Nd3+ ions in a calcium gadolinium germanium garnet was obtained in the interval from ambient conditions up to 23 GPa in order to test its suitability as an optical pressure sensor. Although several Nd3+ non-equivalent centers are present in this garnet, which complicates the assignation of the optical transitions, the R1,R2 → Z5 transitions are unequivocally characterised and fit the requirements of an ideal optical pressure sensor. Results obtained for these emission peaks indicate large pressure coefficients of −8.8 and −10.8 cm−1 GPa−1; meanwhile, the rest of the R1,R2 → Z1−4 emissions remain almost unchanged under pressure. This behaviour is ascribed to the influence of the crystal-field at high pressure on the Z5 Stark level of the ground state and can be easily reproduced exclusively by varying the cubic term of fourth rank of the crystal-field Hamiltonian, which accounts for the Nd3+ ions and is related to medium Nd3+-oxygen distances. These coefficients are larger than those found for the R-lines of Cr3+ in ruby, −7.56 cm−1 GPa−1, suggesting that this system may be a good candidate for a luminescence pressure sensor.

Synthesis and near-infrared luminescence properties of LaOCl:Nd3+/Yb3+

Near-infrared emitting phosphors LaOCl:Nd3+/Yb3+ were prepared by the solid-state method, and their structures and luminescent properties were investigated by using X-ray diffraction and photoluminescence analysis, respectively. The studies shows that tetragonal LaOCl:Nd3+/Yb3+ can be synthesized by the solid-state reaction at 600°C for 3h. Upon 353nm UV excitation, LaOCl:Nd3+/Yb3+ sample shows strong near-infrared emission lines in the region of 1060–1150nm (corresponding to 4F3/2→4IJ′ transition of Nd3+, J′=9/2, 11/2, 13/2, 15/2) and 980–1050nm (corresponding to 2F5/2→2F7/2 transition of Yb3+). The decreasing emission intensity of Nd3+ with increasing doping concentration of Yb3+ proved the energy transfer in LaOCl:Nd3+/Yb3+. The possible near-infrared emission and energy transfer mechanism between Nd3+ and Yb3+, as well as the energy transfer efficiency of LaOCl:Nd3+/Yb3+ were discussed.

Crystal growth, Judd–Ofelt analysis and radiative properties of Nd:YAG single crystal grown by HDS

Nd3+-doped Y3Al5O12 single crystal was successfully grown by horizontal directional solidification (HDS) method; in addition optical absorption and fluorescence spectra were measured at room temperature. Base on the Judd–Ofelt theory, the intensity parameters of Nd3+ in YAG crystal grown by HDS were determined, and then three spectroscopic parameter Ωt (t=2,4,6), radiative transition probabilities, radiative lifetime and branching ratios were obtained according to the absorption spectra and fluorescence spectra, and the results were discussed as well. Furthermore, the stimulated emission cross-section of 4F3/2–4I11/2 transition of Nd3+ in YAG crystal grown by the HDS technique was calculated as 17.86×10−20cm2. In comparison with Nd:YAG crystal grown by the Czochraiski technique, those results indicated that lowly Nd3+-doped YAG crystal grown by HDS method had highly efficient stimulated emission for laser materials.

Review of effects of radiation damage on the luminescence emission of minerals, and the example of He-irradiated CePO4

The accumulation of structural damage that is created in minerals upon corpuscular irradiation, has two apparently contrarious effects on their luminescence behaviour. First, irradiation may cause the generation of luminescent defect centres, which typically results in broad-band emissions. Such defect emissions are characteristic of low levels of radiation damage. Second, radiation damage depletes in general the luminescence of minerals, which is associated with broadenings and intensity losses of individual emission lines. Minerals that have suffered elevated levels of irradiation hence tend to be virtually non-luminescent. This review paper aims at giving an overview of the possible correlations of radiation damage and emission characteristics of minerals. After a brief, introductory summary of the damage-accumulation process and its causal corpuscular radiation, an array of examples is presented for how internal and/or external irradiation may change appreciably the emission of rock-forming and accessory minerals. As a detailed example for the complexity of changes of emissions upon damage accumulation, preliminary results of a case study of the photoluminescence (PL) of synthetic CePO4 irradiated with 8.8 MeV He ions are presented. Irradiation-induced spectral changes include (i) the initial creation, and subsequent depletion, of a broad-band, defect-related PL emission of orange colour, and (ii) gradual broadenings and intensity losses of PL lines related to electronic transitions of rare-earth elements, eventually leading to gradual loss of their splitting into multiple Stark levels (shown for the 4F3/2 → 4I9/2 transition of Nd3+).

Temperature-dependent luminescence and temperature-stimulated NIR-to-VIS up-conversion in Nd3+-doped La2O3–Na2O–ZnO–TeO2 glasses

Telluride glasses of the composition xNd2O3–(7−x)La2O3–3Na2O–25ZnO–65TeO2, where (0≤x≤7) were prepared by the melt quench technique. Some physical and optical properties of the glasses were evaluated. The thermal behavior i.e. glass transition and crystallization temperatures were studied by using TGA–DTA technique. Optical properties of Nd3+-doped telluride glasses were investigated between 298 and 700K. Basing on the obtained values of J–O parameter values (×10−20cm2: Ω2=4.49±0.84, Ω4=5.03±0.61, Ω6=4.31±0.73), the radiative transition probabilities (AT), radiative lifetimes (τR), fluorescence branching ratios (β) and emission cross-sections (σem) were calculated for the 4F3/2→4IJ/2 (where J=9, 11 and 13) transitions of Nd3+ ions. The τR value of the 4F3/2 level amount to 164μs and is slightly higher than the measured decay time of 162μs. With the increasing of Nd2O3 concentration from 0.5 to 7.0mol% the experimental lifetime of the fluorescent level decreases from 162 to 5.6μs. The estimated quantum efficiency amount to 100%, based on a comparison of τR and the experimental decay time of a slightly doped Nd3+ telluride glass. An analysis of the non-radiative decay was based on the cross-relaxation mechanisms. The 4F3/2→4I9/2 and 4F5/2→4I9/2 transitions were analyzed with respect to the fluorescence intensity ratio (FIR) and were found to be temperature dependent. Infrared-to-visible up-conversion emissions with a maximum at 603.0 and 635.3nm were observed at high temperatures using the 804nm excitation and are due to the 4G5/2→4I9/2 and 4G5/2→4I11/2 transitions of Nd3+ ions, respectively. The near quadratic dependence of fluorescence on excitation laser power confirms that two photons contribute to up-conversion of the orange emissions. The temperature-stimulated up-conversion excitation processes have been analyzed in detail. The optical results indicate that the investigated glasses are potentially applicable as a 1063nm laser host as well as an optical sensor for temperature measurements.

Nanosecond Laser Lift-Off of a Copper-Indium-Diselenide Thin Film at a Wavelength of 1342 nm

Abstract Indirectly induced laser lift-off occurs at the interface of a transparent film and an underlying absorbing substrate. Induced laser ablation often referred to as “laser lift-off” is much more energy efficient than direct laser writing. In this paper we report on the selective laser structuring of copper-indium-diselenide (CIS) film on a molybdenum layer at a wavelength of 1342 nm with nanosecond pulses by indirectly induced laser ablation. A wavelength of 1342 nm was chosen, because the CIS layer can act as a transparent film there and this wavelength can be generated with industrial reliability by a laser transition in Nd:Vanadate.

Highly sensitive optical thermometry through thermally enhanced near infrared emissions from Nd3+/Yb3+ codoped oxyfluoride glass ceramic

Under 980nm diode laser excitation, the near infrared (NIR) emissions originated from the 4F7/2/4S3/2→4I9/2 (∼750nm), 4F5/2/2H9/2→4I9/2 (∼803nm), and 4F3/2→4I9/2 (∼863nm) transitions of Nd3+ ions in Nd3+/Yb3+ codoped oxyfluoride glass ceramic were obtained and studied as a function of temperature in the range of 303–623K. It was observed that these NIR emissions were greatly enhanced with the increase of temperature. An explanation based on the luminescence decay curves was given, and it was found that the thermally enhanced phonon-assisted energy transfer (ET) from Yb3+ to Nd3+ played an important role in such phenomenon. In addition, by using the fluorescence intensity ratio technique, the optical thermometry behavior based on the NIR emissions of Nd3+ ions was investigated. Using the 750 and 863nm emissions from the Nd3+/Yb3+ codoped glass ceramic, higher sensitivity for temperature measurement can be achieved compared to the previous reported rare earth ions fluorescence based optical temperature sensors. Due to its thermally enhanced NIR emissions, the Nd3+/Yb3+ codoped oxyfluoride glass ceramic is a promising candidate for optical temperature sensors with high sensitivity and good accuracy.

Hypersensitive Transition of Nd(III) Complexes in Liquids Detected by Pulsed-Laser-Induced Photoacoustic Spectroscopy

Laser-induced photoacoustic (PA) spectroscopy for the spectral measurements of extremely weak absorption such as a forbidden transition of lanthanide ions in liquids has been established. In spectroscopy, a pulsed Nd:YAG laser connected with a MOPO series optical parametric oscillator which emits a broad spectrum covering UV and visible regions is used as the excitation source, and the induced PA signals are detected by an optimized PA piezoelectric transducer. The absorption spectra of trivalent lanthanide ions (\(\text{ Pr}^{3+}, \text{ Ho}^{3+}\), and \(\text{ Nd}^{3+})\) in aqueous solutions have been obtained by the detection system with a detection-limit absorbance of \(1.3\times 10^{-5}\,\text{ cm}^{-1}\) at room temperature. In addition, the effects of different binding environments on the band shapes and oscillator strengths of the hypersensitive transitions of \(\text{ Nd}^{3+}\) ions, i.e., \(\text{ Nd}(\text{ CH}_{3}\text{ COO})_{3}\)\(\cdot \)\(\text{ H}_{2}\text{ O}\) dissolved in \(0.1\,{\text{ mol}} \cdot \text{ l}^{-1}\) acetic acid and \(\text{ Nd(3-butanedione)}_{3}{\cdot } 2\text{ H}_{2} \text{ O}\) dissolved in triglycol compared with \(\text{ NdCl}_{3}\) in \(0.1\,{\text{ mol}}\cdot \text{ l}^{-1}\) hydrochloric acid, are observed. The results show that the chemical environment around the lanthanide ions has great impact on 4f–4f transitions, which is rationalized as the impact in terms of ligand (or solvent) special structures and coordination properties.

Ion clock and search for the variation of the fine-structure constant using optical transitions in Nd13+and Sm15+

We study ultranarrow $5s_{1/2}$ - $4f_{5/2}$ transitions in Nd$^{13+}$ and Sm$^{15+}$ and demonstrate that they lie in the optical region. The transitions are insensitive to external perturbations. At the same time they are sensitive to the variation of the fine structure constant $\alpha$. The fractional accuracy of the frequency of the transitions can be smaller than $10^{-19}$, which may provide a basis for atomic clocks of superb accuracy. Sensitivity to the variation of $\alpha$ approaches $10^{-20}$ per year.

Spectroscopic investigations on Pr3+ and Nd3+ doped strontium–lithium–bismuth borate glasses

Spectroscopic investigations on different concentrations (0.1, 0.5, 1.0, 1.5 and 2.0mol%) of Pr3+ and Nd3+ doped strontium lithium bismuth borate glasses have been done. X-ray diffraction, SEM with EDS, absorption and luminescence spectra were recorded for all the glass matrices and analyzed. X-ray diffraction profiles and SEM images conformed amorphous nature of investigated glass samples. EDS spectra of host glass and Pr3+doped glass matrices gave information about the chemical composition of glass samples. From the absorption spectra of Pr3+ and Nd3+ ions, Judd–Ofelt (J–O) intensity parameters (Ωλ,λ=2, 4 and 6) have been calculated and compared with other glass matrices. The emission characteristics such as radiative lifetimes (τR), measured and calculated branching ratios (β) and stimulated emission cross-sections (σP) have been obtained for the observed emission transitions of Pr3+ and Nd3+ ions in the above glass matrix for all the concentrations. From the emission spectra of Pr3+ and Nd3+ doped glass matrices, the effect of concentration on the quenching of intensity of 1D2→3H4 transition of Pr3+ ion and 4F3/2→4I9/2, 4I11/2 and 4I13/2 transitions of Nd3+ have been studied and discussed.

Lattice distortion and corresponding changes in optical properties of CeO2 nanoparticles on Nd doping

Doping of Nd distorts the lattice structure of CeO2, increases the lattice strain and expands the lattice. Oxygen vacancies and other ceria related defects contribute to the lattice strain. Shifting and broadening of the F2g Raman peak of doped sample, compared to pure CeO2, is indicative of local structure distortion on doping. Dopant induced enhancement of oxygen vacancies, in the CeO2 lattice, is further confirmed by the generation of a new Raman peak at 543 cm−1 that is otherwise absent in the pure one. UV–vis spectroscopy gives an understanding of the different types of f–f electronic transition of Nd in the crystalline environment of CeO2. Effective band gap of CeO2 reduces upto Nd concentration of 2.5%. The band gap, however, increases at 4% of Nd due to Burstein–Moss shift. Photoluminescence intensity of pure CeO2 decreases with Nd concentration owing to the increase in the number of non radiative oxygen vacancies. These vacancies act as luminescence quencher and reduce the emission intensity. Photoluminescence excitation spectra confirm the presence of these oxygen vacancies in the CeO2 nanocrystallites.

Ground- and excited-state absorption and emission spectroscopy of Nd:GGG

Complete room temperature absorption, excited-state absorption and emission spectra of Nd:GGG have been registered and calibrated in cross section units in the near infrared around the main pump and laser emission transitions of Nd:GGG.

Frequency doubling and sum-frequency mixing operation at 4692, 471, and 473 nm in Nd:YAG

We report CW blue laser operation at 469.2, 471, and 473 nm by efficient intracavity second-harmonic generation and sum-frequency generation of the R2→Z5 (938.5 nm) and R1→Z5 (946 nm) F43/2→I49/2 intermultiplet transitions in Nd:YAG with an LiB3O5 nonlinear crystal. Single-wavelength laser operation at 469.2 nm and multiwavelength operation at 469.2, 471, and 473 nm are obtained with maximum output powers of 1.4 and 0.15 W, respectively, by using a glass etalon as frequency selector. The 469 nm blue laser is an efficient pumping source of Pr3+-doped materials.

Efficient diode-pumped Nd:GGG laser operation at 933.6 and 937.3 nm

CW laser emission on the quasi 3-level (4F3/2→4I9/2) transition in Nd:GGG is reported for different pump focusing and resonator dimensions. A nearly hemispherical plano-concave resonator led at 937.3 nm to a maximum output power of 4.1 W for an incident pump power of 21.7 W, thus corresponding to a slope efficiency of about 23.5%. Laser operation was also obtained for the first time around 933.6 nm by using a glass etalon for frequency selection with a maximum output power of 2.3 W and a slope efficiency of 16% with respect to the incident pump power. Dual-wavelength operation (around 933.6 and 937.3 nm), which offers a potential source to generate THz radiation, is also reported.

Fine and hyperfine structure of the transition of ND() in vibrational excited states

The deuterated radical ND was produced in a DC discharge cell cooled at liquid nitrogen temperature. The discharge proved to be vibrationally hot, therefore the transient species could be detected in its vibrational excited states up to v = 6. By scanning in the 431–531 GHz frequency region, several fine-structure components of the transition in vibrational excited states were observed, each of them showing a complex hyperfine structure. A global analysis, including the measured frequencies and previous submillimetre-wave and infrared data, allowed an accurate determination of the equilibrium spectroscopic parameters of the ND radical including fine and hyperfine constants. A very precise determination of the equilibrium bond length r e was obtained. This value is not consistent with the value reported in the literature from NH data. This incongruity was discussed in terms of the breakdown of the Born–Oppenheimer approximation. In view of the recent detection of ND in a solar-mass protostar [A. Bacmann et al., Astron. Astrophys. 521, L42 (2010)], an extended spectroscopic characterization of this deuterated isotopologue of the NH species may prove useful, considering the large deuterium enhancement observed in molecular clouds.

An all-solid-state laser source at 671 nm for cold-atom experiments with lithium

We present an all solid-state narrow line-width laser source emitting $670\,\mathrm{mW}$ output power at $671\,\mathrm{nm}$ delivered in a diffraction-limited beam. The \linebreak source is based on a fre-quency-doubled diode-end-linebreak pumped ring laser operating on the ${^4F}_{3/2} \rightarrow {^4I}_{13/2}$ transition in Nd:YVO$_4$. By using periodically-poled po-tassium titanyl phosphate (ppKTP) in an external build-up cavity, doubling efficiencies of up to 86% are obtained. Tunability of the source over $100\,\rm GHz$ is accomplished. We demonstrate the suitability of this robust frequency-stabilized light source for laser cooling of lithium atoms. Finally a simplified design based on intra-cavity doubling is described and first results are presented.

All-solid-state CW Nd:LuVO4-LBO laser at 533 nm under direct 888 nm pumping

We report an efficient laser emission on the 1066 nm 4 F 3/2 to 4 I 11/2 transition in Nd:LuVO4 under the pump with diode laser at 888 nm. Continuous wave (CW) 11.2 W output power at 1066 nm is obtained under 18.3 W of incident pump power; the slope efficiency with respect to the incident pump power was 71.9%. Moreover, intracavity frequency doubling with LiB3O5 (LBO) nonlinear crystal yielded 4.2 W of green light at 533 nm. An optical-to-optical efficiency with respect to the incident pump power was 23.0%.

CW red light generated by intracavity frequency doubling of a 1329 nm Nd:CNGG laser with LBO

We report an efficient laser emission on the 1329 nm 4F3/2 to 4I13/2 transition in Nd:CNGG under the pump with diode laser at 885 nm. Continuous wave (CW) 3.37 W output power at 1329 nm is obtained under 17.4 W of incident pump power; the slope efficiency with respect to the incident pump power was 36.2%. Moreover, intracavity frequency doubling with LiB3O5 (LBO) nonlinear crystal yielded 822 mW of red light at 665 nm. An optical-to-optical efficiency with respect to the incident pump power was 4.7%.