Spectroscopy of f-f radiative transitions of Yb3+ ions in ytterbium doped orthophosphates at ambient and high hydrostatic pressures

Studies of absorption and luminescence spectra, and luminescence decay times of the intrashell f-f transitions of Yb3+ ions in bulk orthophosphates at different temperatures and at high hydrostatic pressures are presented. The spectroscopic properties of Y0.99Yb0.01PO4 crystal with a tetragonal zircon structure and Gd0.99Yb0.01PO4 and La0.95Yb0.05PO4 crystals with a monoclinic monazite structure are compared. Experiments at ambient pressure were performed at temperatures from 10 to 295 K whereas measurements at high pressure were performed in a diamond-anvil cell at 10 K with a pressure up to 160 kbar. The results reveal a high thermal and pressure stability of the optical properties of the examined crystals as well as the dependence of Yb3+ emission properties on the local symmetry of the site occupied by the ytterbium dopant.