Investigation on a four-beam serial laser combination for a non-collinear scheme based on Brillouin amplification

A non-collinear laser beam combination based on Brillouin amplification was proposed. The influence of non-collinear Brillouin amplification on the combination efficiency was analyzed and discussed theoretically. It was shown that the efficiency of 80% can be achieved with the angle between the Stokes and the pump limited in the range of 90 mrad. According to the theoretical results, a four-beam non-collinear combination experiment was designed and carried out. The output energy of 189 mJ at 10 Hz was achieved with the energies of the four pumps being 70.4, 71.3, 78.9 and 70.1 mJ, respectively. In order to simplify the scheme and reduce the optical loss, a construction of SBS cell for non-collinear combination of multiple beams was also designed.