Compact, high-average-power, nanosecond multi-pass Nd:YVO4 Innoslab amplifier

We reported on a compact, nanosecond multi-pass Nd:YVO₄ Innoslab amplifier. A diode-pumped Q-switched Nd:YVO₄ laser generating 6 W, 5 ns pulses with the repetition rate of 30 kHz was introduced as the seed. With effective shaping designs for seed laser, mode matching and sufficient coverage of gain volume were achieved. After the seed laser passed gain medium eight times, a high average output power of 92 W was achieved, and the corresponding extraction efficiency was 31.9 %. The beam quality factor M² in the two orthogonal directions was 1.89 and 1.38, respectively.