Spectroscopic assessment of Tm3+:GdAl3(BO3)4 crystal as a potential diode pumped laser near 1.9μm

The spectroscopic properties of GdAl3(BO3)4:Tm3+ single crystal for the Tm3+ transition near 1.9μm are presented. The absorption cross section, the emission cross section, and the potential laser gain near 1.9μm are investigated for both σ and π polarizations. The broad absorption band at about 797nm and high value of the above cross section are promising features for obtaining a laser diode pumped Tm3+ laser. The maximum emission cross sections are 1.29×10−20 and 6.60×10−20cm2 at 1.85μm for the σ and π polarizations, respectively. The potential laser gain curves indicate that more than 200nm tunability range is expected for this material.