大气湍流对多抖动法相干合成技术中相位调制信号的影响

分析了大气湍流对采用多抖动法实现的相干合成阵列光束中相位调制信号的影响. 文章首先根据广义惠更斯-菲涅耳原理,采用折射率结构函数对大气湍流进行描述,推导了多抖动法相干合成中阵列光束通过大气湍流后相位调制信号的一般表达式. 在此基础上进行数值模拟,分析了传输距离、湍流强度、光束阵列占空比和光斑尺寸等因素对相位调制信号的影响. 研究发现随着传输距离的增大,相位调制信号强度会先增大后减小,存在一个极大值点;随着湍流强度的增强,相位调制信号强度极大值点的出现距离不断缩短;当光束阵列占空比一定时,随着光斑尺寸的增大关键词：大气湍流相干合成多抖动法相位调制

Effect of atmosphere turbulence on phase modulation signals in coherent beam combination with multi-dithering technique

The effect of atmosphere turbulence on phase modulation signal in coherent beam combination with multi-dithering technique is studied. Analytical formulas for the phase modulation signal of beam array propagating in a turbulent atmosphere are derived based on extended Huygens-Fresnel integral. Then the effects of propagation distance, turbulence intensity, filling factor and size of beam array on phase modulation signal are numerically calculated. The results show that with transmission distance increasing, there occurs a maximum of the amplitude of phase modulation signals. With the intensity of atmosphere turbulence increasing, the maximum of amplitude of phase modulation signals will appear in a shorter distance. When fill factor does not change, the distance between the laser source and the maximum of amplitude of phase modulation signals will be increased with of the dimension of laser beam increasing. When the dimension of laser beam does not change, the distance between the laser source and the maximum of amplitude of phase modulation signals will be increased with fill factor decreasing. Finally, the effects of parallel beam array and conformal focused beam array on phase modulation signal are compared, finding that the distance between the laser source and the maximum of amplitude of phase modulation signals can be changed by changing the focusing distance of conformal focused beam array.