LD pumped laser MOPA system with a phase conjugating mirror of a fused silicon rod

Fused silica is used as the material of the phase conjugated mirror. In the LD pumped laser MOPA system, phase conjugation through the stimulated Brillouin scattering is realized at the repetition frequency of 100 Hz and 400 Hz. At the repetition frequency of 100 Hz, the beam quality factor reached 1.74 in x direction and 1.66 in y direction after double-pass amplification. The highest reflectivity is 24.33% with the input energy of 60.1 mJ, the pulse duration is compressed from 60 ns to 31.34 ns. At the repetition frequency of 400 Hz, the beam quality factor reached 2.10 in x direction and 2.12 in y direction after double-pass amplification. The pulse duration is compressed from 56.69 ns to 28.84 ns.