数字全息再现像的激光散斑消除的研究

由于数字全息图受到激光散斑影响,使得其再现像产生较为严重的噪音。通过详细分析激光散斑形成的原因,并提出了用同一物体的多幅全息图的强度再现像叠加来减小激光散斑的干扰。具体分析了该方法的原理：在记录全息的物体照明光路中加入一散射体,在散射体的M个不同位置记录M张同一物体的全息图,然后将M幅数字全息的再现像叠加,激光散斑噪音下降为M~(-1/2)。最后给出了实验结果。

Reduction of speckle noise in digital holography

As digital holography is influenced by the laser speckle noise,the reconstructed image of digital hologram is seriously ruined by the noise.Based on the cause of laser speckle,a technique of superpesition on an intensity basis of digital reconstructed ima- ges of the same static object is proposed,which achieves the aim of reducing speckle.The theory is discussed in detail:a diffuser is placed in the optical setup,and M holograms are obtained in the M different positions of the diffuser,and then the M reconstructed ima- ges are added on an intensity basis,at last the speckle noise is reduced from 1 to M~(-1/2).The experiment results are given in the end.