Spectroscopic properties of Nd:Gd0.89La0.1NbO4 mixed laser crystal

A Nd-doped niobate mixed laser crystal of Nd0.01:Gd0.89La0.1NbO4 (Nd:GLNO) has been grown successfully by Czochralski method. The absorption spectrum, fluorescence spectrum and fluorescence decay curve of Nd:GLNO crystal were measured at room temperature. The spectral parameters of Nd:GLNO crystal were obtained based on Judd-Ofelt (J-O) theory calculation. The three intensity parameters Ωt(t=2, 4, 6) were calculated to be 6.61, 1.43 and 3.31 × 10-20 cm2, respectively. On the base of the Ωt calculation, the branching ratios, spontaneous radiative probabilities, radiative lifetime and fluorescence quantum efficiency of the 4F3/2 level have been evaluated. Compared with other Nd-doped niobate laser crystal, Nd:GLNO shows a special spectral properties due to the large structure disorder caused by La3+. All the results demonstrate that this crystal is a specific low symmetrical laser material different from other niobates family crystals such as Nd:GdNbO4 (Nd:GNO) and Nd:YNbO4 (Nd:YNO) and can be considered as a promising laser material suitable for laser diode pumping.