Growth of Tm:Lu3Al5O12 single crystal fiber from transparent ceramics by laser-heated pedestal method and its spectral properties

Abstract

Tm:Lu3Al5O12 (Tm:LuAG) single crystal fiber (SCF) with a diameter of 0.6 mm and a length of 140 mm was grown from transparent ceramics by laser-heated pedestal growth (LHPG) method. The growth, Tm3+ ion distribution, absorption spectrum, Judd-Ofelt (J-O)parameter and emission spectrum of SCF are discussed in detail. The test results show that the diameter fluctuation of the SCF is less than 2% and the Tm3+ ion distribution is relatively uniform. J-O theory was applied to analyze the absorption spectrum. With the J-O intensity parameters Omega(t(t=2,4,6)), the emission probabilities, fluorescence branching ratios and radiative lifetimes for the Tm:LuAG SCF and transparent ceramic were all calculated. The stimulated emission cross-section of the(3)F(4)-> H-3(6) transition was obtained by using the Fuchtbauer-Ladenburg (F-L) method. After comparison, it is found that the spectral performance of Tm:LuAG SCF has been improved to a certain extent on the basis of transparent ceramics. It has the potential to be applied to fiber lasers.