Reduction of speckle noise in the reconstructed image of digital hologram - art. no. 683227

A fundamental problem in optical and digital holography is the existence of speckle noise in the reconstructed image. Many approaches have been carried out in order to overcome this problem. In this paper a new technique to reduce the speckle noise is proposed based on the physical nature of speckle noise. The illumination direction of the object beam is changed to provide a different phase information for the same recorded object in an off-axis digital holographic setup and the holograms are recorded with different illumination directions. Then the intensity information of the reconstructed images is superposed and averaged to reduce the speckle noise. The theoretical analysis and experimental results are shown to valid our proposal. They prove that the technique can effectively reduce the speckle noise without ruining the object information.