Research On Reconstructed Image Of Digital Holography

Digital holography is a mix of optical holography, photoelectrical imaging technology and computer technology,. It utilizes charge coupled device (CCD) to record holograms instead of silver print which is used for the recording medium in optical holography and use computer programming to reconstructed the original object numerically. The digital holography pick up the reconstruction time by full numerical recording, storing and reconstructing process, and we can use mature digital image processing technology to dispose the reconstructed image to make it clear.In this paper, we introduce the development, application and study keystone of digital holography based on summarized the history and development of optical holography. Expound the principle of optical and digital holography and build the numerical model of recording and reconstructing process. Then we elicit the location of reconstructed image and the conditions of experiments, such as the range of recording distance and angle between the object light and the reference light.we research on the reconstructed arithmetic and the processing technology of reconstructed image.(1) Analyze the theory and application conditions of convolution arithmetic and fresnel arithmetic, simulated the recording and reconstructing process of off-axis fresnel hologram by MATLAB programming, Reconstruct the real digital hologram received from optical experiments, compare the reconstructed image with simulated results, validates the correctness of theory.(2) Introduce phase-shifting technology which is used in off-axis holography for filtering the zero-order diffracted image and conjugate image, testified by simulated results. Discuss the U filtering, frequency filtering and Differential grads operator, prove and compare their efforts on filtering the zero-order diffracted image.