Search

Abstract: Yb:YAG single crystals with Yb doping concentration 5.4, 16.3, 27.1, 53.6, and 100at.% were grown by the Czochralski process. The effects of Yb concentration on the absorption spectra (190–1100nm), fluorescence spectra under 940nm and X-ray excitation were studied. The concentration quenching of fluorescence was observed when the Yb doping concentration reaches to as high as 27.1at.% for Yb:YAG. Under 940nm excitation, the influence of the self-absorption at 969 and 1029nm on the fluorescence spectra is not evident when the Yb doping concentration is as high as 27.1at.%. However, it can greatly change the shape of fluorescence spectra of Yb:YAG when the Yb doping concentration reaches to above 53.6at.%. [Copyright &y& Elsevier]

Abstract: Yb3Al5O12 single crystal has been grown by Czochralski (CZ) method. The absorption spectrum was investigated at low temperature and the electronic energy levels for 2F5/2 multiplet of Yb3+ in YbAG was proposed. The up-conversion emission of the crystal under 940nm diode pumping and the X-ray excited luminescence (XEL) features of the crystal were also studied. [Copyright &y& Elsevier]

Abstract: Infrared (1.2–1.6μm) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05at.%) ions, was investigated under CW laser diode pumping (λ =940nm). The Cr4+ emission band was observed with its peak at 1.34μm and measured to be about 1.3 times with respect to Yb3+ IR luminescence (λ =1.03μm). We demonstrate that for the excitation wavelength of 940nm Yb3+ ions act as sensitizers of the 3B2(3T2)–3B1(3A2) emission of Cr4+ ions. This crystal is promising as a high-efficient system for tunable laser (1.2–1.6μm) output. [Copyright &y& Elsevier]