Segmented growth of monoclinic Yb:KY(WO(4))(2) on KY(WO(4))2(2) substrates was successfully implemented and its excellent laser performance demonstrated. High slope efficiencies up to 80% and an output power of 375 mW were achieved under Ti:sapphire laser pumping in the continuous-wave regime. In the passively mode-locked regime, pulses as short as 99 fs with an average output power of 69 mW were obtained.