相干合成系统的抖动对远场的影响

Influence of system jitter on far field of coherently combined beam

为了研究相干合成系统的抖动对远场的影响,以正六边形列阵为模型,采用傅里叶光学分析法,得到了系统抖动造成单个光源引入相位差时的远场光强表达式,描绘了中心光斑能量与总能量的比值以及峰值光强随相差的变化曲线,研究了列阵中某个光源位相在不同范围内随机抖动的影响。结果表明,系统抖动引起了远场中心光斑的能量以及峰值光强的减小,远场对称性也遭到破坏;如果将系统的抖动控制在3π/8范围内,远场并不会受到较大影响。

In order to study the effect of system jitter on the far field of coherently combined beam, based on a hexagonal laser array and Fourier optics, the expression of far-field energy distribution with phase difference induced by the jitter of the system was obtained. The expression describes the variation of the maximum intensity and the ratio of the energy of the central lobe to the total energy with the phase jitter of one light source. The effect of the random jitter of an optional light source in the array changing in different ranges was studied. It was found that not only the energy of central lobe and the maximum intensity were reduced due to the system jitter, but also the far-field symmetry was affected, and that far-field of the combined beam was affected only a little with the system jitter controlled within the range of 3π/8.