8 ns fiber laser Q switched by the resonant saturable absorber mirror

We demonstrate that resonant high-modulation-depth saturable absorbers allow efficient pulse shortening in Q-switched lasers. Using a 70% modulation depth resonant saturable absorber mirror we achieved 8 ns pulses that are close to the limit set by the cavity length and are, to our knowledge, the shortest pulses demonstrated to date from passively Q-switched fiber lasers.