Abstracts 2001

Abstract of Publication No. 411

S. Heer, M. Wermuth, K. Krämer, D. Ehrentraut and H. U. Güdel
Up-conversion excitation of sharp Cr3+ 2E emission in YGG and YAG codoped with Cr3+ and Yb3+
J. Lumin. 94-95, 337-341 (2001)      Full Text (PDF)      DOI-Link     

Abstract: The 2E 4A2 emission of Cr3+ in crystals and glasses is of great importance in science and technology. We found a new excitation mode for this emission in the garnets YGG and YAG codoped with Cr3+ and Yb3+. It is based on an up-conversion mechanism using 2F5/2 of Yb3+ as an intermediate state. Excitation of the Yb3+ in the near infrared around 1000 nm leads to visible Cr3+ 2E 4A2 emission around 700 nm at low temperatures. The up-conversion luminescence intensity shows a strong temperature dependence due to an intrinsic loss mechanism. The up-conversion excitation spectra follow the Yb3+ 2F7/2 2F5/2 absorptions. From its time dependence the up-conversion mechanism is found to be dominated by an energy transfer step: Two excited Yb3+ ions simultaneously transfer their 2F5/2 excitation to Cr3+.

Last modified: 13.12.11 by Gabriela Frei