High Power Quasi-Continuous-Wave Diode-End-Pumped Nd:YAG Slab Amplifier at 1319 nm

We report a high power high beam quality quasi-continuous-wave (QCW) diode-end-pumped Nd:YAG slab amplifier at 1319 nm. The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating design. In a five-pass configuration, the amplifier yields a 42.3 W linearly polarized 1319 nm output at repetition rate of 1 kHz with pulse duration of 75 μs and beam quality factors of M_x²=1.13 and M_y²=2.16 in the orthogonal directions. The fluctuation of the amplifier output power is measured to be ±0.6 %. Furthermore, a computational model of QCW pulse amplification is employed to examine the amplification process.