Microscopical Method by Digital Micro-Holography

Digital microscopic holographic recording and numerical reconstruction and the lateral resolution of holographic system were analyzed. Based on off-axis lensless Fourier transform digital holography the two popular phase reconstruction methods proposed by T. Colomb and by S. De Nicola were discussed and simulated. The results show that both the automatic phase compensation approach and the lateral shearing interference combining DH approach are effective for phase measurement of microstructure object. Moreover, an effective method to eliminate the linear term of the shearogram automatically have been proposed and demonstrated. The simulating results demonstrate the validity of the proposed method. It also indicates that to obtain correct phase image the phase difference between the two adjacent pixels of the shearogram map must be less than 2¿.