High-energy nanosecond thin-rod laser amplifier based on Yb:YAG.

Nanosecond pulsed lasers with repetition rates that can deliver tens of millijoules of energy have significant application prospects as seed sources for Joule-scale laser amplifiers to achieve high-energy output. In contrast to the high-average-power and high-repetition-rate scheme, we have developed a compact thin-rod amplifier to obtain high-energy pulses with lower repetition rates. A maximum pulse energy of 30 mJ was generated at a repetition rate of 5 Hz with a pulse duration of 10 ns. To the best of our knowledge, these experimental results represent the highest pulse energy outputs obtained using thin Yb:YAG-based rods at 293 K. The output light exhibits linear polarization because of the quarter-wave plate (QWP) and polarization beam splitter (PBS). This study paves the way for a simple and cost-efficient method to achieve compact tens of millijoules of energy output.