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 M2 factors better than 1.1 and 1.3 at the oscillator and amplifier, respectively.