Compact 532 nm Laser With 59 mJ Pulse Energy Output

We have developed an external frequency doubling Nd:YAG laser with high beam quality, side-pumped by a high-temperature semiconductor laser. The beam quality was optimized using an unstable resonator configuration combined with a variable reflectivity mirror (VRM). This setup, coupled with the high-temperature side-pumping of the Nd:YAG laser crystal and external frequency doubling, resulted in highly stable 532 nm laser output. At a pump current of 100 A and a repetition rate of 50 Hz, the laser produced single-pulse energy of over 50 mJ, with a pulse width of 10.5 ns, and a beam quality factor of $M^{2} \approx 5.5$ . The system demonstrated continuous operation for 300 seconds with output energy stability fluctuations of less than 5%. This work presents a compact, high pulse energy green laser, providing a technological reference for airborne high pulse energy laser systems.