Upconversion emission of Er3+/Yb3+-codoped silicate glass micro-particle under high excitation intensity

The silicate glass micro-particles of co-doped with Er3+ and Yb3+ were prepared by a combustion process and characterized from the spectroscopic point of view, with the aim of investigating the effect and mechanisms of upconversion emissions. The upconversion emissions at 522nm and 547nm have been obtained by exciting the silicate glass micro-particle [about 30μm in diameter] under 976nm diode laser excitation. The excitation intensity was up to about 1800W/cm2. It was observed that the intensity ratio of the 522-nm emission to the 547-nm emission (I522nm/I547nm) in silicate glass increased when increasing the excitation intensity. I522nm became larger than I547nm when the excitation intensity was above 300W/cm2. It is proposed that the phenomenon resulted from the rise of the temperature of the sample measured.