Thermal and spectral characterization of Cr3+:MgWO4-a promising tunable laser material

This paper reports the growth, thermal and polarized spectral properties of Cr3+:MgWO4 crystal. Cr3+:MgWO4 crystal with dimensions of 20×18×13 mm3 was grown successfully by a top-seeded solution growth method. The average thermal expansion coefficients are 10.47×10−6 K−1, 15.68×10−6 K−1 and 10.75×10−6 K−1 along a-, b- and c-axis, respectively. The thermal conductivity is 8.69 W/(m K) at room temperature. Both of the absorption and emission spectra show strong polarization characteristics. There is a broad and strong absorption band at around 790 nm, which means that Cr3+:MgWO4 crystal is suitable for AlGaAs laser diode pumping. The crystal has a broad emission band at 961 nm with a full width at half-maximum of 202 nm; the emission cross-section is about 1.8×10−19 cm2. The results show that Cr3+:MgMoO4 crystal can be regarded as a potential tunable laser gain medium.