Mingjun Song

Structure, thermal and spectroscopic properties of Tm3+-doped Li3Ba2Y3(MoO4)8 crystal as a promising candidate for 2 μm lasers

Tm3+:Li3Ba2Y3(MoO4)8 crystal has been grown by the top seeded solution growth (TSSG) method from a flux of Li2MoO4. The crystal crystallizes in the monoclinic system with the space group C2/c, and the unit cell parameters are a = 5.2052(6), b = 12.6763(17), c = 19.107(3), β = 91.293(12)°, V = 1260.4(3). The thermal expansion, polarized absorption and fluorescence spectra of the crystal were measured and the main spectroscopic parameters were calculated. The broad absorption bands and the large absorption cross sections around 800 nm of Tm3+:Li3Ba2Y3(MoO4)8 crystal indicate that the crystal is very suitable for diode-laser pumping. On the other hand, the broad emission bands around 2 μm show that the crystal is a potential medium for tunable and short pulse lasers.

Crystal Growth and Spectroscopic Investigations of Tm3+:Li3Ba2Gd3(MoO4)8 Crystal

Tm3+:Li3Ba2Gd3(MoO4)8 crystal has been grown by the top seeded solution growth (TSSG) method from a Li2MoO4 flux. The room temperature polarized absorption spectra, fluorescence spectra, and fluorescence decay curves of the crystal were measured. Based on the Judd-Ofelt (J-O) theory, the main spectroscopic parameters of the crystal, including the spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were calculated and analyzed. The broad and strong absorption bands of the crystal show that it can be efficiently pumped by the diode laser, while the large emission cross-sections of the 3F4 → 3H6 transition indicate that the crystal is a promising candidate for tunable and short pulse lasers.

Crystal growth and spectral characterizations of Ho 3+ -doped Li 3 Ba 2 La 3 (MoO 4 ) 8 crystal

Abstract A large Ho 3+ :Li 3 Ba 2 La 3 (MoO 4 ) 8 crystal with high optical quality and well-developed appearance was grown by the flux method. The main spectral properties of the crystal, including the absorption spectra, fluorescence spectra and fluorescence decay curves were recorded at room temperature. The Judd-Ofelt (J-O) theory was applied to calculate the oscillator strength parameters Ω t ( t =2, 4, 6), spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes of Ho 3+ ions undergoing transitions from ground state 5 I 8 to the excited states. The stimulated emission cross-section for the 5 I 7 → 5 I 8 transition was estimated to be 1.32×10 −20 cm 2 at 2045 nm by Fuchtbauer-Ladenburg (F-L) equation and the quantum efficiency of the 5 I 7 level was calculated to be 89%.