Abstract-A ytterbium-doped, glass, channel waveguide laser, fabricated by ion exchange, is reported. The 2.2-cm long device, using broad-band 4% output couplers, lased in the vicinity from 1020 to 1030 nm when pumped by a Ti : sapphire laser operating at 910 nm. A lasing threshold of 50 mW (launched pump) and a slope efficiency of 5% were measured. Device parameters, including fluorescence lifetimes, emission and absorption cross sections, propagation losses, and mode profiles were experimentally determined and laser performance was analytically modeled using this data.