34.3 W, 172 µJ, 1342 nm picosecond master oscillator power amplifier

A high-power, high-energy 1342 nm picosecond Nd:YVO₄ master oscillator power amplifier (MOPA) laser system was demonstrated, comprising a SESAM mode-locked oscillator, a regenerative amplifier, and four main amplification stages consisting of two double-pass amplifiers and two single-pass amplifiers. Low-doping Nd:YVO₄ crystals with undoped end caps, combined with 880 nm laser diode in-band pumping technique, were used to mitigate thermal effects. A pulse energy as high as 710 µJ at 10 kHz was obtained from the regenerative amplifier. Finally, the system produced 34.3 W, 15.4 ps pulses with 172 µJ energy, and 11 MW peak power at 200 kHz, which is the highest average power of 1.34 µm picosecond lasers so far. The beam quality was well maintained, with an M² factor of ∼1.31, using a spherical aberration self-compensation method. The power stability was RMS = 0.89% over 3 hours.