基于相干合成的中继镜系统光束上行传输分析

Analysis of Uplink Propagation in Relay Mirror System Based on Coherent Beams Combination

建立了以相干光束阵列作为光源的中继镜系统模型,光源相位分布由随机并行梯度下降算法优化控制;定义了上行接收光束强度分布不均匀影响因子并分析了上行传输过程的评价函数;在H-V5/7模型大气湍流条件下分别计算了以相干光束阵列作为光源和以平台截断光束作为光源的中继镜系统的上行传输效能。结果显示,利用随机并行梯度算法控制多光束相干合成实现中继镜系统光束上行传输,系统上行传输能量耦合效率和上行接收光束强度均匀性均得到了有效的提高。对10 km上行传输过程,系统评价函数由0.6730提升至0.8838;对30 km上行传输过程,系统评价函数由0.4266提升至0.8560。

Model of a relay mirror system with source composed of coherent beam array is established.Phase distribution of the source is optimized by using the stochastic parallel gradient descent algorithm.The influence factor induced by the intensity non-uniformity of receiving beam is defined and the evaluation function of uplink propagation process is theoretically analyzed.Under H-V5/7 turbulent model,performances of uplink propagation in the relay mirror systems with coherent beam array source and flat beam source are calculated.Results show that power coupling efficiency of uplink propagation and intensity uniformity of received beam are both effectively improved by using the coherent multi-beams array controlled by the stochastic parallel gradient descent algorithm.The evaluation function of 10 km uplink propagation is improved from 0.6730 to 0.8838 and the evaluation function of 30 km uplink propagation is improved from 0.4266 to 0.8560.