High power compact UV lasers with diffraction limited beam are required for industrial applications such as laser direct
imaging, wafer inspection or photo voltaic. By use of a Nd:YVO<sub>4</sub> oscillator with a Saturable Bragg Reflector and a
single pass amplifier, 73 W output power in mode-locked operation at 80 MHz have been generated with high peak
power. By use of two LBO crystals a third harmonic output power of 35 W at 355 nm was demonstrated with an M<sup>2</sup>
value of <1.2. This corresponds to 48% nonlinear conversion efficiency.