Reconstruction Method of Wavefronts in Digital Micro-Holography

The recording and reconstruction for off-axis lensless Fourier digital hologram is analyzed. The phase reconstruction method based on the digital lateral shearing interferometry and digital holography has been discussed and demonstrated. The results show that the phase image of microstructure object can be obtained by combining the digital holography with lateral shearing interferometry. Based on the idea of automatic phase compensation method proposed by S. De Nicola et al., an effective approach to eliminate the linear term of the shearogram automatically is proposed and also demonstrated. The results show that the standard one-dimensional phase unwrapping must be applied to the original phase map before the procedure of lateral shearing. It is also shown that to obtain correct reconstruction the phase difference between the two adjacent pixels of the shearogram map must be less than 2¿ . Moreover, the smaller the pixel size of the reconstructed image plane is, the more accuracy of phase image will be obtained.