Dopant partitioning influence on the near-infrared emissions of Tm3+ in oxyfluoride glass ceramics.

The doping distribution of Tm3+ ions in a transparent oxyfluoride glass ceramic has been investigated. Optical absorption, luminescence, and excitation measurements have been performed in order to determine the environment in which Tm3+ ions and the infrared emissions they give rise to are located. An interesting result has been found: the main contribution to the 1465 nm emission (S band) is due to Tm3+ ions in the crystalline phase for low doping level. However, when the Tm3+ concentration is high the S-band emission comes from the small portion of Tm3+ that remains in the vitreous phase. It has been concluded that cross relaxation (CR) processes are responsible for the quenching of the S-band emission in the crystalline phase for high doping concentration. Lifetime measurements of the 3H4 level have also been taken and the probability of CR processes deduced. [ABSTRACT FROM AUTHOR]