Erbium (Er)- and Ytterbium (Yb)-codoped monoclinic KLu(WO4)2 single crystals were grown by top seeded solution growth-slow cooling method for several different doping concentrations. Growth parameters have been optimized to obtain macrodefect-free single crystals. Er energy levels involved in the 4I13/2-->4I15/2 were determined by 6 K polarized optical absorption. The maximum emission cross section for this electronic transition has been evaluated, being 2.85x10(-20) cm2 for E||Nm at 1535 nm. Laser oscillation in the 1.5 microm range was obtained by pumping the Yb ion at 980 nm and sensitizing Er. The maximum output power achieved was 152 mW, with 1.2% slope efficiency.