湍流对离轴列阵高斯光束相干与非相干合成的影响

Influence of turbulence on the coherent and incoherent combinations of off-axis Gaussian beams

研究了湍流对离轴列阵高斯光束相干与非相干合成的影响.推导出了相干合成光束的传输方程.采用二阶矩束宽、桶中功率和参数β作为光束质量评价参数比较了离轴列阵高斯光束通过湍流大气的相干与非相干合成,并对主要结果给予了合理的物理解释.研究表明:一方面,不论是相干合成还是非相干合成,湍流都使得合成光束扩展、峰值光强下降,并且子光束数越多,合成光束受湍流影响就越小.另一方面,非相干合成光束较相干合成光束受到湍流的影响要小.

The influence of turbulence on the coherent and incoherent combinations of off-axis Gaussian beams is studied in detail. The analytical propagation equation of the resulting beam in turbulence for the incoherent combination is derived. The mean-squared beam width, the power in the bucket and the β parameter are taken as the characteristic parameters of beam quality to compare the results of coherent and incoherent combinations of off-axis Gaussian beams propagating through atmospheric turbulence, and the reasonable physical explanations are also given. It is shown that, on one hand, both for the incoherent and coherent combinations the turbulence results in a beam spreading and a degradation of the maximum intensity, and the larger the individual beam numbers is, the less sensitive is the resulting beam to the effect of turbulence. On the other hand, the resulting beam for the incoherent combination is less affected by turbulence than that for the coherent combination.