Transitions Of Pr3 Research Articles

Spectroscopy of the IR transitions in Pr3+ doped heavy metal selenide glasses

The spectral properties of Pr 3+ doped BaInGaGeSe chalcogenide glasses are reported. Absorption spectra, emission spectra, and lifetimes of the lower lying manifolds have been measured. Radiative transition rates are calculated and compared with measured experimental lifetimes. The strong mid-IR emission and spectral properties of this glass make this glass a strong candidate for lasers, amplifiers, and high brightness sources in the mid-IR.

Homogeneous broadening and hyperfine structure of optical transitions in Pr3+:Y2SiO5.

Homogeneous broadening and hyperfine structure of optical transitions in Pr3+:Y2SiO5.

Electric-field-modulated photon echoes in Pr^3+:YAlO_3

We measured the Stark coefficient for the (3)H(4)(1) ? (1)D(2)(1) transition of Pr(3+):YAlO(3), using the technique of Stark-modulated photon echoes. This gave a value of 58 kHz/(V cm(-1)) for the vector difference between ground-and excited-state electric dipole moments. The resolution with which Stark shifts could be measured in these experiments was ~500 Hz, which is more than an order of magnitude less than the homogeneous linewidth.

Fast fluorescence and scintillation of Pr-doped yttrium aluminum perovskite

Spectroscopy of Pr-doped YA1O3 (YAP) has been investigated under synchrotron radiation and laser excitations. Fast UV fluorescence was shown to be due to allowed d–f transitions of Pr3+. Light yield of Pr-doped YAP has been measured in comparison with Ce-doped YAP. The relatively low scintillation efficiency of Pr: YAP is explained by the very different concentration of the dopant ions in both systems and by the presence in Pr: YAP of Ce trace impurities which can act as trap centers for the fast UV scintillation of Pr3+ ions.

Intra-4f2 two-photon transitions in Pr3+ : LiYF4

The study of3H4 →3PJ (J = 0,1,2) and1I6 direct two-color two-photon transitions in Pr3+ : LiYF4 as a function of laser wavelength, polarization, intensity, and sample temperature leads to an identification of several energy levels which were not observed before in one-photon spectroscopic measurements.

Modified Judd–Ofelt technique and application to optical transitions in Pr3+-doped glass

An extension of the Judd–Ofelt technique [B. R. Judd, Phys. Rev. 127, 750 (1962)] is introduced in which measured fluorescence branching ratios are incorporated into the calculation of the Judd–Ofelt parameters. It is found that including branching ratio measurements into the analysis allows the Judd–Ofelt parameters to be reliably calculated with fewer ground-state absorption measurements than would otherwise be necessary. The method is applied to Pr3+:ZBLAN glass, an important material for 1.3 μm optical amplifiers. A closed-form expression is also derived for determining the Judd–Ofelt parameters from ground-state absorption data.

Energy levels of Pr3+ ions in halide crystals

Energy levels of f-f transitions of Pr3+ ions in LaF3+ ions in LaF3, PrF3 and LaCl3 single crystals have been determined from optical absorption and emission studies at cryogenic temperatures. Older data are revised considerably, with strong changes in the energy-level positions of the 1D2, 3P0 and 3P1 states.

Variation of the Pr^3+ nuclear quadrupole resonance spectrum across the inhomogeneous optical line in Pr^3+:LaF_3

We report nuclear quadrupole resonance (NQR) frequency and linewidth variations of the Pr3+ ground-state hyperfine levels for various positions within the 3H4(Γ1)–1D2(Γ1) inhomogeneous optical line and satellite transitions of Pr3+:LaF3. A linear increase in the broadening of the Pr3+ hyperfine transitions, without a shift of central frequency, is measured by the Stark modulated optical pumping hole-burning technique as the laser is tuned toward the wings of the inhomogeneous optical transition. The linear variation is attributed to electric quadrupole broadening caused by changes in the local density of point defects across the Stark-broadened optical transition. The optically detected NQR spectra of the satellite transitions associated with Pr ion pairs are shifted in frequency and for most satellites are narrower than the NQR spectra found in the wings of the main inhomogeneous optical line.

Electric quadrupole allowed transitions of lanthanide ions in octahedral symmetry

The calculation of the electric quadrupole oscillator strength for a transition between the crystal field levels Γ′ and Γ″ of a lanthanide ion in octahedral symmetry is presented. The calculated values are < 10-12 in most cases, except for the (6F1/2)Γ6 ← Γ7(6H5/2) transition of Sm3+ in Cs2 NaSmCl6, where the value of 2·3 × 10-10 is in agreement with experiment at 300 K. The oscillator strength for the (3F3)Γ5 ← Γ1(3H4) transition of Pr3+ in PrCl3- 6 is 8·8 × 10-13, so that an observed zero phonon line close to the calculated wavenumber of this transition, but whose intensity is 1·7 × 104 times greater, does not correspond to it. Additional information from vibronic analysis, magnetic dipole and electronic Raman line strength calculations enable reassignments to be made for the 3F3 term of Pr3+.

Compositional Dependence of the Quantum Efficiency of the Transition at 1.3 μm of Praseodymium in Halide Glasses

ABSTRACTAn improvement in the quantum efficiency of the 1.3 μm transition of Pr3+ has been acheived as a result of doping alternative halide glasses. An increase from 3.4% in ZBLAN [1] to 9.9% in a multicomponent halide glass is reported.

Manifestation of electron–phonon interaction in insulating crystals doped with Pr3+ ions

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Laser Spectroscopy of Solids

Remarkably narrow optical homogeneous linewidths of the order of 1 kHz have now been observed in low temperature zero-phonon transitions of dilute impurity ion crystals, such as Pr3+ in LaF3. Novel nonlinear optical resonance techniques have been devised for this purpose using ultrastable phase locked cw dye lasers where the measurements are performed either in the frequency domain (hole burning) or in the time domain (coherent optical transients). These studies effectively bring the Mossbauer effect into the optical region. Hence, the observed linewidths are no longer limited by inhomogeneous strain broadening (∼5 GHz) or even by static local fields due to neighboring spins (∼100 kHz). However, weak magnetic field fluctuations from local spins are readily detected. As an example, spin decoupling and line narrowing, which are well known in NMR, are observed in an optical transition of Pr3+: LaF3 at 2 K where the F19–F19 dipolar interaction is quenched and the optical linewidth drops from 10 to 2 kHz, clearly demonstrating the spin broadening mechanism. Results will be discussed in terms of a Monte Carlo line broadening theory.

Optical hole burning by superhyperfine interactions in CaF_2:Pr^3+

Optical hole burning has been observed in the 5941-A transition of Pr(3+) in a charge-compensated tetragonal site of CaF(2) . The Pr(3+) ground state is doubly degenerate and shows a large first-order hyperfine splitting, which is clearly resolved because of the very narrow inhomogeneous linewidth of 650 MHz. The hole burning involves a new mechanism, in which optically induced spin flips of neighboring nuclei (here (19)F) shift the optical transition frequency outside its homogeneous linewidth. This mechanism was confirmed by optical rf double resonance.

Effect of electron correlation on the forced electric dipole transition probabilities infNsystems

Results of model studies of the impact of electron correlation on the forced electric dipole transition probabilities between states of the 4fN configuration are reported for the [3 P]0↔[3 F]4, [3 H]4 transitions in Pr3+: LaCl3 and for [7 F]0↔[5 D]2, [7 F]1↔[5 D]1 hypersensitive transitions in Eu3+: LaCl3. For the former system the correlation effects cause a modification of the Judd-Ofelt results by 40–95 per cent, whereas for the latter the probability changes by as much as two orders of magnitude. The great changes found in the case of hypersensitive transitions suggest that electron correlation effects may belong to the most important factors determining the nature of these transitions. Several types of effective correlation operators are considered and their relative importance is discussed. The results indicate that intermediate configurations including g orbitals are very important for the description of correlation effects.

Intensity calculations on hypersensitivef-ftransitions in nine-coordinate lanthanide systems of trigonal symmetry

Dipole strength and intensity calculations are reported for a series of 4f-4f electronic transitions in Pr3+, Eu3+, Tb3+ and Ho3+ complexes of trigonal symmetry. These calculations are based on crystal field and intensity models which include both multipole-point charge and multipole-induced dipole lanthanide-ligand interactions. The ligand parameters appearing in these models are atomic charges, atomic dipolar polarizabilities and atomic positional coordinates. Term-to-term transitions are characterized according to (1) their magnetic dipole versus electric dipole character, (2) the mechanism principally responsible for their electric dipole strength and (3) their sensitivity to ligand structure. Where it is possible to make comparisons, the calculated intensity results for term-to-term transitions are in excellent qualitative and good semiquantitative agreement with experiment. The calculations reported here represent the first full scale computational test of a 4f-4f intensity model which includes both the Judd-Ofelt static coupling and Mason, Peacock and Stewart dynamic coupling (or ligand polarization) contributions to the electric dipole strengths of 4f-4f transitions in noncentrosymmetric lanthanide complexes.

Concentration independence of photon echo lifetimes in Pr^3+:LaF_3

Photon echo studies of the concentration dependence of the homogeneous lifetime, T2′, of the 3H4 → 3P0 transition of Pr3+ in LaF3 indicate no dependence over the range 0.01 to 1.0 at. %. This shows that multipolar, exchange, and spin-flip effects on T2′ are much smaller than the measured value, T2′ = 515 ± 11 nsec. Also, additional experimental confirmation of earlier theories of echo energy dependence on optical thickness is obtained.