Single crystal Tm 3+ :SrMoO 4 was grown successfully by Czochralski technique along the (001) orientation in N 2 atmosphere. The refractive index of SrMoO 4 crystal was measured at room temperature. The linear thermal expansion coefficients along c- and a-axes were measured to be 1.70×10 −5 °C −1 and 0.59×10 −5 °C −1 , respectively. Its polarized absorption spectra, fluorescence spectra and fluorescence decay curve have also been investigated at room temperature. Based on the Judd–Ofelt theory, the intensity parameters have been determined as: Ω 2 =7.875×10 −20 , Ω 4 =2.797×10 −20 and Ω 6 =0.92×10 −20 cm 2 . The radiative probabilities, radiative branching ratios, radiative lifetimes and stimulated emission cross sections of Tm 3+ in SrMoO 4 were obtained. The quantum efficiency of the 3 H 4 level is determined to be approximately 88.56% for this material.