线阵光纤阵列相干合成光束的远场光功率分布

Far field power distribution of coherent beam synthesized withlinear fiber array

激光相干合成所得光束的远场能量分布直接影响其实际应用。针对基于四芯线阵光纤阵列的激光相干合成研究了远场能量分布。采用高斯分布函数近似描述单模光纤出射光束能量分布,推导合成光束的远场能量分布的一般表达式,用MATLAB进行数值计算,并搭建实际相干合成系统进行测试以验证计算结果。研究结果表明:四芯线性光纤阵列的相干合成光束能量近似高斯分布,横向截面内表现为两两组合所形成的三种周期六种干涉场的叠加。实验结果与理论计算吻合,研究对光纤阵列相干合成光束的远场应用具有指导意义。

The far field energy distribution of the laser coherent beam synthesized by linear fiber array source directly affects its practical application. The farfield energy distribution ofthe laser coherent beam combined bya four- core fiber array is studied. The energy distributionof the light beam emitted from a single mode fiber is approximately described by Gauss distribution function. A general mathematic expression is derived and further numerical calculation is carried out through MATLAB. A testing system ofthe energy distribution is built to verify the calculation results. The research results show that the laser beamcoherentlysynthesized from the four- core linear fiber array isapproximately Gaussian distribution,and the far field spot is composed of six interference fields of three different periods,which is resulted from six different combinations of the four cores. The experimental results agree well with the theoretical calculation. This researchhas a guiding significance for the far field application of optical fiber array coherent combination.