Spectroscopic properties and fluorescence dynamics of Er 3+ and Yb 3+ in CaYAlO 4

Abstract

The optical properties of Er 3+- and (Er 3+, Yb 3+)-doped CaYAlO 4 single crystals grown by the Czochralski technique are presented. These crystals emit infrared fluorescence in the eye-safe spectral region around 1.55 μm. The measured electric dipole oscillator strengths of the transitions between the J manifolds at 300 K are compared with those derived from the Judd-Ofelt theory. The non-radiative relaxation rates from the various excited states are determined by calculating the difference between the measured fluorescence decay rates and the calculated radiative transition rates. The stimulated emission cross sections are determined from the absorption spectra with the aid of the reciprocity method. The properties of the (Er 3+, Yb 3+)-doped CaYAlO 4 single crystals are compared with those of the well-known phosphate glass.