STUDY OF ENERGY-TRANSFER FROM YB3-EARTH SILICATES AND BORATES( TO ER3+ IN RARE)

On the basis of luminescence lifetime studies we have determined the e nergy transfer parameters and population evolution for the F-2(5/2)(Yb 3+), I-4(11/2) and I-4(13/2) (Er3+) energy levels in single crystals o f ScBO3 (SBO), LaSc3(BO3)(4) (LSB), LiY(BO3)(3) (LYE) and CaGd4Si3O13 (CGS), codoped with Yb3+ and Er3+. For the first time we have studied the interaction of dopants in CGS, GSAG and CaYAlO4 (CYA) with the ion -relaxator Ce3+. Fast and efficient energy transfer to the laser level is achieved in LSB-Yb, Er, When energy is transferred from Yb to Er i n CGS. the level I-4(11/2) is populated. This level is affected by rev erse energy transfer? excited state absorption and accumulation. The p opulation of this level could be reduced by an order of magnitude usin g Ce3+ ions as a dopant.