偏振方向对阵列光束远场能量分布的影响

为了研究相干合成系统发光单元的偏振方向对相干合成远场光强分布的影响,以1维线性分布的阵列为例,利用傅里叶方法分析得到了单个发光单元的偏振方向偏离时相干合成的远场光强的解析表达式。数值计算结果表明:光源偏振方向的偏离使得远场中心光斑的峰值光强减小,光强的最小值不再为零,次瓣所包含的能量增大,但图样仍成对称性分布。对于5个单元合成系统,当单个发光单元偏振方向偏离π/2时,峰值光强减小到原来的68%左右。

Influence of polarization direction on far field distribution of laser array

To study the influence of polarization direction on far field of laser array with coherent combining, an one dimension analyses model of fiber laser array is established, and using Fourier optics, the expression for the far field intensity of coherent combining beams is deduced when the polarization direction of a single cell is deviated. Numerical calculation results show that, with the increasing of the deviation the maximum intensity of center lobe reduces, and the minimum intensity is no longer zero. The deviation of the polarization direction will not change the symmetry of the energy distribution. For the the array with 5 fiber lasers, when the deviation angle is π/2, the peak intensity will reduce to about 68% of the original．