High beam quality and high energy short-pulse laser with MOPA

A high energy, high beam quality short-pulse diode-pumped Nd:YAG master oscillator power-amplifier (MOPA) laser with two amplifier stages is demonstrated. The two-rod birefringence compensation was used as beam quality controlling methods, which presents a short-pulse energy of 40 mJ with a beam quality value of M² = 1.2 at a repetition rate of 400Hz. The MOPA system delivers a short-pulse energy of 712.5 mJ with a pulse width of 12.4 ns.The method of spherical aberration compensation is improved the beam quality, a M² factor of 2.3 and an optical-to-optical efficiency of 27.7% is obtained at the maximum laser out power.The laser obtained 1.4J out energy with polarization integration.