Pulse shortening by a nonlinear mirror mode locker

Frequency-doubling mode locker: the influence of group-velocity mismatch

The influence of the group-velocity mismatch between the fundamental and the second harmonic in the frequency-doubling nonlinear mirror is investigated theoretically. The nonstationary analysis provides an estimation for the maximum pulse-shortening capabilities of the device when it is used as a passive mode locker. The pulse-shape deformation is also investigated.

Frequency-domain analysis of the mode-locking process in a laser with a second-harmonic nonlinear mirror

We present a computer simulation of the mode-locking process in a pulsed Nd:YAG laser with a nonlinear mirror based on second-harmonic generation. For the first time to our knowledge, a frequency-domain description of the passive mode-locking process is presented, which provides complete information for the amplitude and phase evolution of the individual modes. The mode locking is described as being due to the interaction of the longitudinal modes in the nonlinear mirror through second-harmonic and sum- and difference-frequency generation.