Efficient third-harmonic generation with a Ti-sapphire laser

We report the highest efficiency (to the best of our knowledge) third-harmonic generation from a gain-switched Ti:sapphire laser. Using Type I LBO crystals, we obtained ~45 % conversion in the sum-frequency stage and ~35% overall conversion from the fundamental. The diode-laser-injection-seeded Ti:sapphire laser operated in 920-960 nm range to provide 307-320-nm UV energy.