Room temperature cw laser action of Yb3+-doped KY(WO4)(2) and KGd(WO4)
(2) crystals at 1.025 mu m and Er,Yb:KY(WO4)(2) at 1.54 mu m has been
demonstrated under pumping by both Ti-sapphire laser and InGaAs laser
diodes. A slope efficiency of Yb-lasers up to 78% has been obtained.