基于空间部分相干光相干度分布的全息图计算方法

A new design method for computer-generated holograms based on coherence degree of spatially partially coherent light

在计算机全息图的计算过程中,引入的随机相位与光学重建中相干光散射会引起再现像中的散斑噪声现象,从而影响重建图像的质量。提出了一种新的基于部分相干光相干度分布的全息图计算方法,即PCL-GS算法,算法以Shell衍射定理为基础,模拟参考光源相干度对全息记录过程的影响,使模拟记录过程更接近实际状况。在重建光相干度相同的情况下,与传统GS算法重建结果相比,重建图像的峰值信噪比提升4.8%、结构相似度提升14%、散斑对比度降低4%。方法可为三维全息显示、光束整形等光调制技术提供新的理论基础。

In computer-generated hologram(CGH)calculation,the introduction of random phase and coherent light can result in speckle noise in reconstructed images,which affects the image quality.A new CGH calculation method named partially coherent light GS(PCL-GS)algorithm is proposed based on shell theorem to simulate the effect of the coherence of reference light source on hologram recording process,which makes the simulation recording process closer to the actual physical situation.Compared with traditional method,peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)of reconstructed image are improved by 4.8%and 13%respectively.And the speckle contrast(SC)is reduced by 4%.Numerical simulation and optical reconstructions are performed to verify the feasibility.The proposed method could also provide new application prospect for three-dimensional holographic display,beam shaping and other light modulation techniques.