The performance of lasers based on channel waveguides produced by proton implantation in Nd:YAG crystals through an electroformed mask is reported. The fabrication method used can produce several waveguide lasers in the crystal by a single implantation process with very good optical performance. The analysis and comparison of the main laser emission features, as well as the propagation losses of these waveguides, by using different output couplers in the laser cavity is also presented.