LD-pumped all-solid-state 355 nm ultraviolet picosecond pulse laser

A laser diode (LD) end-pumped Nd∶YVO4 all-solid-state ultraviolet picosecond(PS) pulse laser was demonstrated under the semiconductor saturable absorption mirror(SESAM) mode-locking technology and the PS pulse laser regeneration amplifier technology, by using the type-Ⅰ-phase-matched LiB3O5(LBO) as the second harmonic generation(SHG) crystal and the type Ⅱ-phase-matched LBO as the third harmonic generation(THG) crystal. Finally, the 355 nm UV laser was obtained with 129.6 J single pulse energy, 17 ps pulse width at 1Hz repetition rate while the pump power was 5 W. The third harmonics were up to 60.3% conversion to 532nm and 16.6% to 355nm and the single pulse energy fluctuation was less than 0.58% in 3h operation.