Nonlinear mirror mode locking of a cw Nd:YLF laser

Passive mode locking of a cw lamp-pumped Nd:YLF laser with the nonlinear mirror technique is reported. Nearly transform-limited pulses of 13-ps duration and 1.5-W average power at 1.047 microm have been obtained. The nonlinear mirror consists of a lithium triborate frequency-doubling crystal and a dichroic mirror with high reflectivity for the second harmonic and lower reflectivity for the fundamental frequency. The mode-locking process is self-starting, with pulse duration and stability strongly dependent on the cavity parameters.