An average power of 58 W, pulse width of 40 ps at 1 KHz repetition rate of Nd:YAG picosecond laser is reported. It used an etalon to directly get pulse width of 135 ps from Nd:YVO4 mode locked laser in 1064 nm, which repetition rate was 88 MHz. When the seed pulses were injected into the double length of regenerative LD side-pump Nd:YAG cavity at 1 KHz repetition rate, the single pulse energy was amplified to 3 mJ, the pulse width was compressed to 99 ps, beam quality of M^2 factor was 1.3. The single pulse energy was amplified up to 58 mJ, the pulse width was self compressed to 40 ps, beam quality of M^2 factor was approximately 3.5 after single passing three stages of double high gain LD side-pump Nd:YAG module. Beam pointing was about 40 urad. The stability for pulse to pulse RMS was less than 3%. A thin-film polarizer and a quarter-wave plate was inserted into the regenerative amplification cavity to let pulses double travel the same geometric path basis on pulse polarization. Serrated aperture were used in the amplification. That's beneficial to decrease the nonlinear effect for the high power in the crystal. High gain LD side-pump Nd:YAG module could lead the pulse energy amplify more and self compress the pulse width. Double length of regenerative cavity was used to enhance the optical cavity length, it greatly decreased the laser's volume and improved stability of picosecond laser. It's a nice way for high power picosecond laser and the laser system would be more simple and smaller.
We present a high compact structure laser diode (LD) side-pumped all-solid-state Q-switched master oscillator power amplifier (MOPA) laser system with high beam quality. Bidirectional voltage-supplied Q-switched and MOPA technologies were introduced in the design. An in-center wavelength of 1064 nm with pulse width adjustability from 5 to 18 ns was obtained at the repetition rate of 500 Hz. Through multistage Nd∶YAG amplifiers at the pulse width of 6 ns, the oscillator was scaled up to 145 W and the corresponding peak power reached 48.3 MW with single pulse energy fluctuation less than 0.45% in 1 h operation.