Theoretical analysis of two-beam coupling three-stage coherent optical amplification

Based on the principle of two-beam coupling,the method of three-stage coherent optical amplification is put forward.Which not only makes it possible that tress pieces of low quality crystals can yield the result that one piece of high quality crystal can reach,but also solves the problem that the amplification coefficient can not be greatly increased by means of one-stage amplification.The feasibility of the method has proved through theoretical analysis.