THE EFFECT OF PRESSURE ON ENERGY-TRANSFER IN CR3-TM3+-YAG()

The effect of pressure on energy transfer in Cr3+:Tm3+:YAG has been co nsidered. We find that pressure increases the separation in energy of the 4T2 and 2E levels of Cr3+ and that this increase leads to both an increase in Cr3+ --> Tm3+ energy transfer efficiency and a decrease in Cr3+ --> Tm3+ energy transfer rate. We attribute the increase in tran sfer efficiency to a reduction in the spin-orbit coupling of the 4T2 a nd 2E levels with increasing pressure and the decrease in transfer rat e to the elimination of the thermal population of the 4T2 level. We in clude a discussion of the relationship of effects of pressure and temp erature on the energy transfer properties of Cr3+.