A high-energy Ho: YLF MOPA system pumped by Tm: YAP lasers

This paper introduces a high-energy Q-switched Ho: YLF master oscillator power amplifier (MOPA) system pumped using linearly polarized Tm: YAP lasers. In this system, the pulse repetition frequency was 100 Hz, and an 84.7 mJ Ho laser was generated with a total pump power of 102.3 W, corresponding to a total optical conversion efficiency of 8.3%. The oscillator yielded a maximum output energy of 20.0 mJ and pulse width of 19.0 ns, corresponding to a peak power of 1.05 MW. Moreover, the amplifier delivered a maximum output energy of 84.7 mJ and pulse width of 18.0 ns, corresponding to a peak power of 4.70 MW. In addition, the system exhibited an excellent beam quality in both directions, with the M-2 factors better than 1.1 and 1.3 at the oscillator and amplifier, respectively.