Reconstruction with collimating reference wave in digital holography microscopy

In order to reconstruct three-dimension micro-object wave field accurately,the reconstruction method with collimating reference wave to reconstruct digital hologram with large numerical aperture was studied by using Fresnel diffraction formula and sampling theorem.The reason that spherical reference wave can't be used to reconstruct a large numerical aperture hologram was analyzed.The expression of reconstructed phase image was presented.As result of the measure error of the recording distance and the offset of the point source,the distortion of the phase image reconstructed with collimating reference wave was also analyzed.Both theoretical analysis and computer simulation show that accurate intensity reconstruction can be obtained as long as a high quality hologram is recorded.Only if the recording distance and the offset of the point source are accurately measured,the correct phase reconstruction can be obtained.Due to a measure error,a quadratic function distortion of the reconstructed phase distribution appears.So it is important to measure the recording parameters accurately in experiment.