Narrow inhomogeneous and homogeneous optical linewidths in a rare earth doped transparent ceramic

Inhomogeneous and homogeneous linewidth are reported in a Eu3+ doped transparent Y2O3 ceramic for the 7F 0-5D0 transition, using high-resolution coherent spectroscopy. The 8.7-GHz inhomogeneous linewidth is close to that of single crystals, as is the 59-kHz homogeneous linewidth at 3 K (T2 = 5.4 μs). The homogeneous linewidth exhibits a temperature dependence that is typical of a crystalline environment, and additional dephasing observed in the ceramic is attributed to magnetic impurities or defects introduced during the synthesis process. The absence of Eu3+segregation at the grain boundaries, evidenced through confocal microfluorescence, further indicates that the majority of Eu3+ions in the ceramic experience an environment comparable to a single crystal. The obtained results suggest that ceramic materials can be competitive with single crystals for applications in quantum information and spectral hole burning devices, beyond their current applications in lasers and scintillatorsThis work was supported by National Science Foundation under award No. PHY-1212462, the European Union FP7 project QuRep (247743), the Spanish Ministry of Economy and Competitiveness (MAT2010-17443) and Comunidad de Madrid (S-2009/MAT-1756

Rare-earth doped transparent ceramics for spectral filtering and quantum information processing

Homogeneous linewidths below 10 kHz are reported for the first time in high-quality Eu3+ doped Y 2O3 transparent ceramics. This result is obtained on the 7F0→5D0 transition in Eu3+ doped Y 2O3 ceramics and corresponds to an improvement of nearly one order of magnitude compared to previously reported values in transparent ceramics. Furthermore, we observed spectral hole lifetimes of ∼15 min that are long enough to enable efficient optical pumping of the nuclear hyperfine levels. Additionally, different Eu3+ concentrations (up to 1.0%) were studied, resulting in an increase of up to a factor of three in the peak absorption coefficient. These results suggest that transparent ceramics can be useful in applications where narrow and deep spectral holes can be burned into highly absorbing lines, such as quantum information processing and spectral filteringThis work was supported by the ANR projects RAMACO (No. 12-BS08-0015-01) and DISCRYS (No. 14-CE26-0037-01), Idex No. ANR-10-IDEX-0001-02 PSL⋆, and Nano’K project RECTUS. C.W.T. and R.L.C. acknowledge support from National Science Foundation (NSF) Award Nos. CHE-1416454 and PHY-1415628 and M.O.R. and L.E.B. from Project No. MAT2013- 43301-R of the Spanish Ministry of Economy and Competitiveness (MINECO) and Comunidad Autónoma de Madrid under Grant No. S2013/MIT-274

Étude du frittage non-conventionnel de céramiques de type YAG:Nd en présence d’ajout de silice

L’objectif de cette étude était de cerner l’influence du procédé de frittage non conventionnel employé pour la mise en forme des pièces (frittage SPS ou post-frittage HIP) sur l’activation des processus densifiants. Il s’avère qu’un traitement SPS des poudres initiales permet d’abaisser la température de début de frittage et conduit dans certaines conditions à des pièces translucides ou transparentes. L’influence de la silice, introduit comme ajout de frittage, et du néodyme, introduit comme dopant, est également discutée dans ce travail. Le post-frittage HIP, quant à lui, permet l’élimination de la porosité résiduelle dans les échantillons, ce qui conduit à la transparence des pièces réalisées

Nd3+-activated CaF2 ceramic lasers

Nd,Y:CaF2 and Nd,La:CaF2 ceramics featuring good optical quality have been fabricated by reactive sintering and a hot isostatic pressing method. The transmission spectra, emission spectra, and fluorescence decay curves were measured. Lasing at 1064 and 1065 nm was observed in Nd,Y:CaF2 and Nd,La:CaF2, respectively, upon quasi-continuous-wave pumping by a diode laser emitting at 791 nm. To the best of our knowledge, this is the first demonstration of Nd3+-activated CaF2 ceramic laser

Thermal and Optical Characterization of Undoped and Neodymium-Doped Y3ScAl4O12 Ceramics

Y3–3xNd3xSc1Al4O12 (x = 0, 0.01, and 0.02) ceramics were fabricated by sintering at high temperature under vacuum. Unit cell parameter refinement and chemical analysis have been performed. The morphological characterization shows micrograins with no visible defects. The thermal analysis of these ceramics is presented, by measuring the specific heat in the temperature range from 300 to 500 K. Their values at room temperature are in the range 0.81–0.90 J g1–K–1. The thermal conductivity has been determined by two methods: by the experimental measurement of the thermal diffusivity by the photopyroelectric method, and by spectroscopy, evaluating the thermal load. The thermal conductivities are in the range 9.7–6.5 W K–1 m–1 in the temperature interval from 300 to 500 K. The thermooptic coefficients were measured at 632 nm by the dark mode method using a prism coupler, and the obtained values are in the range 12.8–13.3 × 10–6 K–1. The nonlinear refractive index values at 795 nm have been evaluated to calibrate the nonlinear optical response of these materials.This work is supported by the Spanish Government under projects MAT2011-29255-C02-01-02, MAT2013-47395-C4-4-R, and the Catalan Government under project 2014SGR1358. It was also funded by the European Commission under the Seventh Framework Programme, project Cleanspace, FP7-SPACE-2010-1-GA No. 263044