Investigation of serial coherent laser beam combination based on Brillouin amplification

Based on transferring energy from multiple pump beams into one Stokes beam using Brillouin amplification, a serial coherent laser beam combination scheme is presented, which has many advantages, such as, simple structure, low cost, ease of adjustment, higher load capability, scalable easily, etc. Furthermore, it has been demonstrated that the combination of several beams using this method is theoretically possible. But in practice, the amplification of high power Stokes beam is a key problem to solve. In this paper, the amplification of Stokes beam whose power is higher than the pump beam is first studied and proved experimentally. Coupling the two laser beams by this method is proved experimentally, and the coupling efficiency reaches more than 80%. Then the feasibility of multiple beams combination based on Brillouin amplification is analyzed and tested theoretically.