平顶高斯光束相干合成在大气湍流中的传输

Propagation of coherent combination of flat-topped Gaussian beams in atmospheric turbulence

光束合成是将多个激光器的输出光束在远场叠加起来,从而实现高功率、高光束质量的激光输出,因此在遥感、跟踪、远距离光通信等领域中具有广泛的应用前景。研究了一维线阵平顶高斯光束的相干合成在大气湍流中的远场传输特性及能量集中度,推导出合成光束的光强传输及桶中功率、二阶矩束宽解析式。研究表明,合成光束随着传输距离的增加,最终演化为类高斯分布。湍流使得光束的峰值光强下降,下降量随着平顶高斯光束的阶数增大而增大。远场能量集中度随着湍流强度增强、光束阶数增大、占空比减小、阵列个数增加而下降。

Beam combination is that laser output beams overlap in the far field,so as to realize the high power,high beam quality of laser output,which has a broad prospect of application in remote sensing,tracking and far distance optical communication.The far field propagation properties and energy centrality of the coherent combination of one-dimensional flat-topped Gaussian beam array through atmospheric turbulent were studied in detail in this paper.The analytical expressions for intensity propagation,power in the bucket（PIB） were derived based on the generalized huygens-fresnel principle.It is shown that coherently combined beam will finally turn into Gaussian-like profile in the far field with increasing the distance of combination beam.The turbulence leads to degradation of the maximum intensity of combination beam,the larger the beam order is,the larger the decrement is.The energy centrality will decrease as the turbulence intensity increases,the beam order increases,the fill factor decreases and the elements number increases.