Pump-power-controlled luminescence switching in Yb3+/Tm3+ codoped water-free low silica calcium aluminosilicate glasses

Intense infrared-to-visible upconversion emissions in Tm3+/Yb3+ codoped water-free low silica calcium aluminosilicate glasses have been obtained under excitation at 976 nm. The results showed that as the pump power/intensity is increased, a reduction of up to one order of magnitude at the 800/480 nm 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. (c) 2007 American Institute of Physics.