Thermally induced threefold infrared-to-visible upconversion emission enhancement in Er3+/Yb3+-codoped Ga2S3:La2O3 chalcogenide glasses excited at 1.064 μm is reported. The times three upconversion efficiency enhancement was achieved by heating the sample in the temperature range of 23–155 °C, and is assigned to the temperature-dependent multiphonon-assisted anti-Stokes sideband excitation process of the ytterbium sensitizer. A theoretical analysis based upon rate equations considering the sensitizer absorption cross section as a function of the phonon occupation number in the host material exhibited very good agreement with experimental data.

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Intense infrared-to-visible upconversion emissions in Tm3+∕Yb3+ codoped water-free low silica calcium aluminosilicate glasses have been obtained under excitation at 976nm. The results showed that as the pump power/intensity is increased, a reduction of up to one order of magnitude at the 800∕480nm emitted intensity ratio is observed; characterizing what can be denominated as luminescent switching. The physical origin of this switching is discussed and explained in terms of the tailoring of luminescent switchers to operate in a large range of pump powers, what could be used in the development of sensors and networks for optical processing and optical communications.

Blue luminescence emission around 480 nm through cooperative upconversion from pairs of Yb 3ϩ ions implanted into 60TeO 2 -10GeO 2 -10K 2 O-10Li 2 O-10Nb 2 O 5 tellurite glasses and excited by a cw laser at 1.064 m is demonstrated. Cooperative luminescence emission enhancement owing to the temperature dependent multiphonon-assisted anti-Stokes excitation process of the ytterbium ions is also observed. The experimental results revealed a fourfold enhancement in the cooperative luminescence emission when the sample was heated in the temperature range of 20°C-260°C. The thermally induced enhancement is assigned to the effective absorption cross-section for the ytterbium ions which is an increasing function of the medium temperature.

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