Enhancement of upconverted luminescence in Er3+: Te O2 glass on increasing the temperature and concentration of Yb3+ beyond the critical limit

Abstract

Enhancement of upconverted luminescence in Er3+ Yb3+: Te O2 has been observed with increase in the concentration of Yb3+ on excitation with 780 nm laser radiation. It is further noted that the upconversion is increased even above the quenching limit on increasing the temperature of the glass. The incident radiation excites Yb3+ indirectly via Er3+ resulting in a strong blue emission from Yb3+ and green and red emissions from Er3+. The UV emission from Er3+ at 380 nm involves three near infrared photons when there is no Yb3+ in the glass but when Yb3+ is also present, this behaves as a two photon process. The lifetime of the S 32 4 level of Er3+ in glasses containing only Er3+ and also those containing both Er3+ and Yb3+ has also been measured in different conditions. © 2007 American Institute of Physics.