Orange emission in Pr3+-doped fluoroindate glasses

We synthesize and study the properties of praseodymium doped fluoroindate glasses. Glass compositions with praseodymium molar concentrations up to 5% were obtained with good optical quality. Thermal, optical, and luminescence properties are investigated. Judd–Ofelt analysis is used to determine radiative lifetime and emission cross-section of the orange transition originating from the 3P0 level. We find that these glasses are good candidates for the realization of blue diode laser pumped orange lasers for quantum information processing applications

Crystallization of ZrF4-LaF3-AlF3 glasses

0.7125ZrF4-0.2375(1 - xLaF3 • xLnF3)-0.05AIF3 with x = 0.01, 0.02 and 0.03 for Ln = Er and x = 0.03 for Ln = Pr, Nd glasses were studied by differential thermal analysis (DTA), X-ray diffraction and optical spectroscopy. Avrami parameters (Ec and n) were obtained from DTA curves. With La3+ substitution a decrease in the stability against crystallization was observed. This decrease follows the order Er3+ > Nd3+ ≈ Pr3+ for 3% molar substitution. n values suggest an interface controlled growth mechanism with grain edge nucleation abler saturation. Two crystalline polymorphs of the LaZr3F15 phase were identified. With the substitution of 3 mol% of Pr3+, Nd3+ or Er3+ for La3+ only the crystallization of the rhombohedral α-LnZr3F15 phase was observed. An increase in Ω6 Judd's intensity parameter occurs with crystallization and also an increase in the 1.04 μm peak emission cross-section for Nd3+ 4I3/2 state suggesting the potential application of these glass ceramics in optical amplification devices. © 1997 Elsevier Science B.V

Hyperfine structure of Tm3+ in YAG for quantum storage applications

International audienceQuantum storage of photons in an atomic ensemble can be obtained by using three-level K systems. In these schemes, two levels are coupled by optical transitions to a third one. Ideally, the two transitions should have similar intensities and long coherence lifetimes. Rare earth ion doped crystals are attractive materials for quantum storage because their hyperfine levels can have coherence lifetimes longer than 100 ls and thus can be used to build K systems. Tm3+ ions are especially interesting since they can be excited by ultra-stable laser diodes. In this paper, the hyperfine structures of the 3H6(0) and 3H4(0) crystal field levels of Tm3+ in Y3Al5O12 are investigated by hole burning spectroscopy under a magnetic field. The results are compared to theoretical calculations and found to be in reasonable agreement. Moreover, it is shown that an appropriate magnetic field is able to relax the selection rule on the nuclear spin projection, an absolutely necessary condition to obtain an efficient three-level K system with Tm3+ in this host. Finally, a magnetic field orientation optimized with respect to the K system transition intensity ratio is predicted for a convenient experimental set-up

Couplage à haute coopérativité d'un ensemble de spins de terres rares à un résonateur supraconducteur utilisant l'orthosilicate d'yttrium comme substrat

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