We have butt coupled 13‐mW cw and 27‐mW (5‐&mgr;s‐long pulses, 5% duty cycle) optical power into a single mode Ti‐LiNbO3optical waveguide by using single‐mode diode lasers at &lgr; = 0.84 &mgr;m. Coupling efficiencies greater than 68% were observed. These are the highest diode‐laser powers coupled by any means into the technologically important class of LiNbO3optical waveguides. Our observations support the theory of butt coupling between injection lasers and waveguides at hitherto unavailable power levels and efficiencies. The light coupled into the waveguide has a substantially reduced incoherent power level when compared to that emitted by the laser.