Growth and optical properties of a new promising laser material Er3+/Yb3+:Ca9Y(VO4)7

Er3+/Yb3+:Ca9Y(VO4)7 crystal with dimensions of Ø 20×25 mm2 was grown successfully by the Czochralski method. Its thermal and spectral properties were investigated in detail. The thermal expansion coefficients are 1.39×10−5 K−1 and 1.63×10−5 K−1 along a-axis and c-axis, respectively. The thermal conductivity is about 1 W/(m K) at room temperature. The absorption bands near 980 nm have a full-width at half-maximum of 37 nm and 26 nm for σ- and π-polarization, respectively. The fluorescence lifetime of the 4I13/2 level of Er3+ is 4.12 ms. The emission cross sections calculated by the Füchtbauer–Ladenburg method at 1533 nm are 1.58×10−20 cm2 and 1.57×10−20 cm2 for σ- and π-polarization, respectively. The results indicate that Er3+/Yb3+:Ca9Y(VO4)7 crystal is a potential 1.5–1.6 μm laser material.