The injection seeder system for the Surelite Family produces ultranarrow single longitudinal mode (SLM) outputs with a smooth temporal profile. Seeding is accomplished by injecting a seed beam from a single mode cw diode pumped fiber laser into the Surelite oscillator. Amplitude pioneered the commercial introduction of this technique and holds the patent on its use with radially variable reflectivity resonator optics*. Important applications that require narrow linewidth include pumping narrow linewidth tunable systems, holography, and Doppler LIDAR.