Two-Beam-Combined 7.4 J, 50 Hz Q-switch Pulsed YAG Laser System Based on SBS Phase Conjugation Mirror for Plasma Diagnostics

Japanese Journal of Applied Physics (Impact Factor: 1.07). 01/2004; 43. DOI: 10.1143/JJAP.43.L1038

ABSTRACT The phase conjugation of the optically nonlinear stimulated Brillouin scattering (SBS) process using heavy-fluorocarbon materials effectively compensated thermal degradation at two amplifier lines, resulting in an output energy of 7.4 J at 50 Hz. When combining two beams, the beat wave generation caused by the temporal coherence between the two beams can be prevented because the two beams leave at intervals longer than the coherence length of the pulse. The use of different Brillouin frequencies of reflection from different SBS substances can also be effective in preventing the interference effect caused by the spatial coherence between the two beams.