提出了一种改进的次谐波大气湍流相位屏模拟方法, 通过对低频相位屏的采样方式进行设计, 能够充分地补偿相位屏中的低频信息.利用该方法对符合Kolmogorov理论的大气湍流相位屏进行数值模拟, 并结合相位结构函数和相对误差函数对所提方法的准确性进行验证, 分析谐波次数和采样点数对模拟相位屏的影响.此外, 还将改进后的次谐波法与经典的功率谱反演法、Zernike多项式法、分形法及改进前的次谐波法进行了对比, 结果表明：改进后的次谐波法对应的相位结构函数与Kolmogorov湍流理论值最符合, 即利用此方法生成的相位屏最准确.

An improved subharmonic method to generate atmospheric turbulence phase screen was introduced. The low frequency phase screen is specifically designed to quickly achieve adequately sampling in low frequency portion of power spectrum. To evaluate the accuracy of the proposed method, the phase structure function of phase screen generated by using this method is calculated and compared with the theoretical Kolmogorov structure function. The accuracy of the simulated phase screen can be improved with the increase of subharmonics. In addition, comparison between the improved subharmonic method and other four phase screen generation methods (standard fast Fourier transform method, subharmonic method, Zernike polynomials method and random mid-point displacement method) is also carried out. The comparative results show that the phase structure function for the improved subharmonic method matches very closely that of Kolmogorov turbulence theory, and it is the best one in comparison with those of other four phase screen generation methods.