Spectroscopic and laser properties of erbium and ytterbium co-doped photo-thermo-refractive glass

Spectral-luminescent characteristics of erbium ions in photo-thermo-refractive (PTR) glasses doped with different concentrations of ytterbium and erbium oxides were investigated in this work. X-ray diffraction pattern of studied glasses was carried out. Judd-Ofelt parameters of intensity Omega(t) were obtained and used for deriving emission cross-sections and radiative lifetimes. It was found that the peak emission cross-sections values at a wavelength of 1.53 mu m obtained from F-L and McCumber methods are 0.59 x 10(-20) cm(2) and 0.60 x 10(-20) cm(2), respectively, which are very similar and compared with those of silicate glasses. A quite high value of quantum yield at the wavelength of 1.53 mu m for the sample with 0.1 mol% Er2O3 co-doped with ytterbium oxide has been investigated. Energy transfer efficiency from ytterbium ions to erbium ones was found to be 80% and 86% for erbium- and 1 mol% and 2 mol% Yb2O3-co-doped PTR glass, respectively. Laser properties of 2Yb-01 Er PTR glass were carried out. The gain spectrum starts to be positive when the population inversion parameter gets to 0.5. Laser action was demonstrated at room temperature. It was found that the round-trip losses of the Er/Yb-PTR element are 0.28%.