500-kHz Level High Energy Double-Pass Nd:YVO4 Picosecond Amplifier with Optic–Optic Efficiency of 51%

We have demonstrated a high pulse energy and high optic–optic efficiency double-pass picosecond (ps) master oscillator power amplifier system of 1064 nm at a pulse repetition rate of 500 kHz. A 500 kHz, 7.68 μJ picosecond laser is used as the seed laser. Through one stage double-pass traveling-wave amplifier, a maximum output power of 16.19 W at a pump power of 31.7 W is generated with the optic–optic efficiency of 51.07%. The output pulse duration is 17.6 ps, corresponding to the pulse energy of 32.38 μJ. The beam quality factor M 2 were measured to be 1.28 and 1.17 along the x, y axis direction, respectively.