Femtosecond passive mode locking of a solid-state laser by a dispersively balanced nonlinear interferometer

A Michelson interferometer containing a nonlinear fiber in one arm and dispersion control in the other arm has been used for passive mode locking of a continuous wave Nd:glass laser. We discuss scaling issues and demonstrate the usefulness of this technique by generating ≊300 fs pulses with only Pf≊15 mW of average power in the fiber and ≊100 fs pulses with a self-starting threshold of Pf≊100 mW.