By exciting at 940 nm, we have characterized the 1.84 μm near infrared emission of trivalent thulium ions in Yb3+, Tm3+:KGd(WO4)2 single crystals as a function of the dopant concentration and temperature, from 10 K to room temperature. An overall 3H6 Stark splitting of ∼470 cm-1 for the Tm3+ ions in the Yb3+, Tm3+:KGd(WO4)2 was obtained. We also studied the blue emission at 476 nm (Tm3+) and the near infrared emissions at 1.48 μm (Tm3+) and 1 μm (Yb3+) as a function of the dopant concentration. Experimental decay times of the 1G4, 3H4, and 3F4 (Tm3+) and 2F5/2 (Yb3+) excited states have been measured as a function of Yb3+ and Tm3+ ion concentrations. For the 3F4→3H6 transition - of Tm3+ ions, we used the reciprocity method to calculate the maximum emission cross section of 3.07×10-20 cm2 at 1.84 μm for the polarization parallel to the Nm principal optical direction.