ABSTRACT
Cooperative luminescence phenomenon of Yb:YAG crystals was studied. Up-converted blue luminescence was obviously observed in Yb:YAG under excitation in the near-infrared region with a wavelength 940 nm. Experimental evidence was provided by the fact that the intensity of 498 nm luminescence shows a quadratic dependence on excitation power, and the intensity of blue luminescence increased with the increase in Yb ion concentration. It is concluded that this luminescence is due to a cooperative process resulting from a strong interaction of Yb ions. The cooperative luminescence is possiblely assigned to the strong interaction of 4f(13) electrons and neighboring Yb3+ ions in a covalent host lattice such as YAG. Theoretical cooperative luminescence spectrum was calculated.
Subject(s)
Luminescence , Nanostructures/chemistry , Ytterbium/chemistry , Aluminum Oxide/chemistry , Crystallization , Energy Transfer , Erbium/chemistry , Holmium/chemistry , Luminescent Measurements/instrumentation , Luminescent Measurements/methods , Spectrophotometry, Infrared , Spectroscopy, Near-Infrared , Yttrium/chemistryABSTRACT
Yb(3)Al(5)O(12) single crystal has been grown by Czochralski (CZ) method. The absorption spectrum was investigated at low temperature and the electronic energy levels for (2)F(5/2) multiplet of Yb(3+) in YbAG was proposed. The up-conversion emission of the crystal under 940 nm diode pumping and the X-ray excited luminescence (XEL) features of the crystal were also studied.
Subject(s)
Aluminum Oxide/analysis , Ytterbium/analysis , Aluminum Oxide/chemistry , Crystallography, X-Ray , Spectrometry, Fluorescence , Spectrophotometry , Ytterbium/chemistryABSTRACT
Infrared (1.2-1.6 microm) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05at.%) ions, was investigated under CW laser diode pumping (lambda=940 nm). The Cr4+ emission band was observed with its peak at 1.34 microm and measured to be about 1.3 times with respect to Yb3+ IR luminescence (lambda=1.03 microm). We demonstrate that for the excitation wavelength of 940 nm 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 (1.2-1.6 microm) output.
