Temperature and pressure dependence of the homogeneous width of 7F0-5D0 electronic transition in Sm2+-doped sodium borate glass

The homogeneous width Γ h of 7F0↔5D0 transition in Sm2+ ions doped into sodium borate glass was determined at T=5-293 K under P=1 bar and at T=5, 80 and 120 K under various P up to 8 kbar. The line width Γ h was obtained from spectral hole burning (SHB) and time-resolved resonant fluorescence line narrowing (FLN) experiments. It was found that at P=1 bar the T-dependence of Γ h changes from Γ h(T)∝T 2 (quadratic) for T<20 K to Γ h(T)∝T (linear) for T>20 K. Under pressure, Γ h grows slightly at all three T values studied (at 80 K by 1.2%/kbar and at 120 K by 1.6%/kbar in the range 0-8 kbar). Possible mechanisms to explain the observed T- and P-dependences of Γ h are briefly discussed