High-Repetition-Rate Guided-Mode Femtosecond Laser

Femtosecond pulse trains in waveguide lasers with high fundamental repetition rates are achieved by exploiting the nonlinearity in the waveguide. Components of the apparatus include an optical resonator, a saturable absorber for starting and stabilizing mode-locking, and a gain element. Part of the laser cavity or the entire laser cavity is made of waveguide or fiber (collectively called “waveguide” herein). The net dispersion of the laser cavity can be anomalous. This anomalous dispersion in combination with the positive self-phase modulation nonlinearity in the waveguide creates soliton formation to shorten the pulse duration in the invented lasers. Conversely, a normal dispersive waveguide with negative self-phase modulation nonlinearity can also be used.