RESONANT-FREQUENCY DOUBLING OF A SELF-STARTING, COUPLED-CAVITY, MODE-LOCKED TI-AL2O3 LASER

We report the efficient frequency doubling of a self-starting, coupled-cavity, mode-locked Ti:sapphire laser (Ti:Al2O3). The laser produced pulses of 2.5-3.4 ps at a 122-MHz repetition rate that were tunable from 740 to 820 nm. These pulses were frequency doubled in an external ring enhancement cavity. Using a 1-mm-long, Brewster-cut LiIO3 crystal, we obtained conversion efficiencies of as much as 34% in the form of picosecond pulses tunable from 370 to 410 nm. The maximum generated power in the blue was 48 mW at 384 nm.