抗大气湍流近红外计算鬼成像

Turbulence-Free Near-Infrared Computational Ghost Imaging

为解决大气湍流造成成像质量严重下降的问题,提出一种抗大气湍流近红外计算鬼成像方法。计算鬼成像利用调制光场和物光总光强进行强度关联来获取图像信息,调制光场是决定成像质量的一个关键。利用湍流随时间和空间变化,将其作为计算鬼成像中的随机调制光场,通过功率谱反演法模拟强、中、弱三种大气湍流引起的相位扰动影响,并加载到光传播链路中完成抗大气湍流近红外鬼成像仿真分析。利用近红外相机作为探测器搭建计算鬼成像实验系统,并进行外场实验对提出的方法进行实验验证。仿真和实验结果表明,仿真三种不同强度湍流情况和外场条件下均能重构出目标物体的像,仿真图像信噪比分别为19.4 dB、24.2 dB和64.58 dB,表明了计算关联成像在近红外波段抗大气湍流的有效性。该方法结构简单,易于实现,可为近红外抗大气湍流探测提供一种技术途径。

As traditional optical imaging is seriously affected by the atmospheric turbulence,a turbulence-free near-infrared computational ghost imaging method is proposed to improve the imaging quality.Computational ghost imaging gets the image information by correlating the modulated light field and the total intensity of light that is transmitted or reflected by the object,where the modulated light field is one of the major factors affecting the imaging quality.Due to the turbulence changes with time and space,it is treated as a randomly modulated light field in this work.We use the power spectrum inversion to simulate the influence of phase disturbance caused by three different atmospheric turbulence intensities(strong,medium and weak),and add the turbulences to the optical propagation path.Finally,a near-infrared camera is used as the detector to realize the computational ghost imaging.The results of simulations show that the peak signal-to-noise ratio of the reconstructed images under three different intensity turbulence conditions are 19.4 dB,24.2 dB and 64.58 dB,respectively.The results demonstrate the effectiveness of the computational ghost imaging against atmospheric turbulence in the near-infrared band.The proposed method is simple in structure and easy to be implemented,which provides a technical approach for near infrared turbulence-free detection.