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The growth and characterization of Cr,Nd:Y3Al5O12 (YAG) crystal are reported. By improving the synthesis and sintering processes of polycrystalline materials, as well as the temperature gradient and annealing atmosphere, a high quality crystal with size of ϕ30 mm × 110 mm is obtained by using the Czochralski technique. After measuring the concentrations of dopant Cr3+ and Nd3+ within the different parts of the grown crystal, it is found that the distribution of dopant ions is uniform throughout the crystal. The fluorescence spectra of Cr,Nd:YAG crystal exhibit intense emissions at 1064 nm under excitations of 808 and 450 nm. The fluorescence lifetime of Nd: 4F3/2 level is obtained to be 234.2 µs. The maximum average output power reaches 7.87 W with a slope efficiency of 31.2% for near‐infrared laser at 1063.9 nm. The above results indicate that Cr,Nd:YAG crystal is a promising gain media for all‐solid state lasers. [ABSTRACT FROM AUTHOR]

The continuously increasing CO2 released from human activities poses a great threat to human survival by fluctuating global climate and disturbing carbon balance among the four reservoirs of the biosphere, earth, air, and water. Converting CO2 to value-added feedstocks via electrocatalysis of the CO2 reduction reaction (CO2RR) has been regarded as one of the most attractive routes to re-balance the carbon cycle, thanks to its multiple advantages of mild operating conditions, easy handling, tunable products and the potential of synergy with the rapidly increasing renewable energy (i.e., solar, wind). Instead of focusing on a special topic of electrocatalysts for the CO2RR that have been extensively reviewed elsewhere, we herein present a rather comprehensive review of the recent research progress, in the view of associated value-added products upon selective electrocatalytic CO2 conversion. We initially provide an overview of the history and the fundamental science regarding the electrocatalytic CO2RR, with a special introduction to the design, preparation, and performance evaluation of electrocatalysts, the factors influencing the CO2RR, and the associated theoretical calculations. Emphasis will then be given to the emerging trends of selective electrocatalytic conversion of CO2 into a variety of value-added products. The structure-performance relationship and mechanism will also be discussed and investigated. The outlooks for CO2 electrocatalysis, including the challenges and opportunities in the development of new electrocatalysts, electrolyzers, the recently rising operando fundamental studies, and the feasibility of industrial applications are finally summarized. [ABSTRACT FROM AUTHOR]

A new laser crystal, Cr/Er/Pr:CaLu0.2La0.8Ga3O7 (Cr/Er/Pr:LuCLGO), was successfully grown by the Czochralski method for the first time. The structural parameters of Cr/Er/Pr:LuCLGO crystal were determined by the x-ray Rietveld refinement method. Optical absorption, fluorescence spectra and lifetime decay profiles were measured for the crystal. The co-doped Cr3+ ion expands the absorption cross-section considerably for 400–700 nm bands, which is beneficial for xenon lamp pumping. Also the co-doped Pr3+ ions decrease the population of the Er3+:4I13/2 energy state effectively. The energy transfer efficiencies of the Er3+:4I11/2 → Pr3+:1G4 and Er3+:4I13/2 → Pr3+:3F4 processes were calculated, showing that Pr3+ ions can play an important role as deactivators for Er3+ ions. Furthermore, the energy transfer mechanisms among Cr3+, Er3+ and Pr3+ ions were studied. The results suggest that Cr/Er/Pr:LuCLGO crystal is a new promising laser medium for 2.7 μm xenon lamp pumping solid-state lasers. [ABSTRACT FROM AUTHOR]