Excitation of the 2F7/2 → 2F 5/2 transition of the Yb3+ ion in Yb3+, Pr 3+-doped fluorozirconate glass at 974 nm results in efficient excitation of the 1G4 level of Pr3+ ion that in turn emits in the middle infrared at ∼3.6 μm. The energy transfer (ET) process Yb3+(2F5/2) → Pr 3+(1G4) is assisted by fast excitation migration among the Yb3+ ions. An upconversion process involving ET from the 2F5/2 level to the 1G4 excited state populates the 3P0 excited state that produces emission at 481, 521, 603, 636, and 717 nm. A study of the behavior of the fluorescence from the 1G4 level at 1325 nm and from the 3P0 level at 603 nm allowed the estimation of the ET rate constants for the processes involved after short-pulsed laser excitation at 974 nm. A rate-equation model was employed to evaluate the population inversion relating to the 1G4 → 3F4 transition of the Pr3+ ion at 3.6 μm under continuous wave pumping.
|Number of pages||10|
|Journal||Journal of the Optical Society of America B: Optical Physics|
|Publication status||Published - 2013|