Er-diffusion doped LiNbO3 is an excellent electrooptic material for active integrated optics. With low loss Ti- diffused waveguide structures and electrooptic intracavity phase- or amplitude modulators modelocked waveguide lasers with pulse repetition rates beyond 10 GHz and Q-switched lasers with pulse peak power levels in the kW-range have been realized. Both types of lasers have been diode-pumped and fully packaged. Harmonic modelocking allows to combine high pulse repetition rates with high peak power levels. Such a laser has been successfully used as key component of a transmitter for nonlinear optical RZ- (soliton-) type data transmission at 10 Gbit/s. Concepts for the stabilization of a single supermode emission as prerequisite for pulses of high amplitude stability and low timing jitter and hence for low error rate transmission are discussed in detail. Results of Q-switched laser operation with folded Mach-Zehnder type switch of high extinction ratio are presented and potential applications of such a source emitting in the eye-save wavelength range discussed.