Site selective upconversion in Nd 3+:KLiYF 5
Abstract
Site selective upconversion of Nd 3+:KLiYF 5 is reported in dilute (0.2% molar) and concentrated (3.4% molar) crystals. On the basis of site selective excitation spectroscopy, the mechanism for upconversion is determined as being due to the sequential absorption of two photons. The excitation spectrum is shown to be composed of features resonant with each of the two stages of excitation. The dilute sample shows site selective upconversion fluorescence throughout the excitation range. For the more concentrated sample, energy transfer amongst the lower states equalises the population of the sites when shelved in the metastable 4F{3}/{2} state so that site selectivity only occurs during the second absorption stage.
- Publication:
-
Optics Communications
- Pub Date:
- February 1997
- DOI:
- 10.1016/S0030-4018(96)00517-2
- Bibcode:
- 1997OptCo.134..398R