3-D reconstruction of phase grating via digital micro-holography

Digital micro-holography technique, a combination of digital holography with microscopy, can be used to measure and analyse the micro-structure and status information of samples when the digital hologram registered is reconstructed numerically by some numerical methods based on the principle of scalar diffraction or coherent image. By summarizing the development of digital micro-holography, Fresnel approximation reconstruction algorithm and two-wavelength technique are introduced to study the three dimensional phase reconstruction of phase grating. Experimental results show good agreement with true parameters of phase grating. It also analyses the aberration of the image reconstructed by Fresnel approximation approach and two-wavelength technique.