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 μJ 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.