两维相干阵激光远场主瓣特性分析

Analysis of Far-field Main Lobe Characteristics of Two-dimensional Coherent Array Laser

研究了两维相干阵激光光束主瓣的远场特性。建立了正方形和正六边形子光源排列的相干阵激光传输的数学物理模型,通过数值模拟与分析得出:采用高斯函数来描述相干阵激光光束的远场中心主瓣光强分布误差很小,可按照单孔径激光器的基模高斯光束传输规律来描述相干阵激光光束的传输规律。在此基础上,计算了远场中心主瓣能量占比,计算结果表明,远场中心主瓣能量占比几乎不受子光源数目的影响;而随着占空比的增加,中心主瓣能量占比逐渐增大。当相干阵激光的孔径完全装填时,正方形排列的激光光束中心主瓣的最高能量占比为79.1%;而正六边形排列的能量占比值为83.2%。

The far-field characteristics of the main lobe of two-dimensional coherent array laser beam are studied.The mathematical and physical models of coherent array laser beam propagation with square and regular hexagonal sub light sources are established.Through numerical simulation and analysis,it is concluded that the error of Gaussian function to describe the far-field central main lobe intensity distribution of coherent array laser beam is very small,and the propagation law of coherent array laser beam can be described according to the fundamental Gaussian beam propagation law of single aperture laser.On this basis,the energy ratio of the central main lobe in the far field is calculated.Calculation results show that the energy ratio of the central main lobe in the far field is hardly affected by the number of sub light sources.With the increasing of duty cycle,the energy proportion of central main valve increases gradually.When the aperture of coherent array laser is completely filled,the maximum energy proportion of the central main lobe of square laser beam is 79.1%,and the proportion of regular hexagonal arrangement is 83.2%.