The Study Of The Arithmetic Of Reconstruct Complex Wave-front In Digital Holography

In digital holography, the hologram is directly recorded on a charge-coupled device(CCD) camera and its reconstruction is carried out by computer numerical calculation instead of optical diffraction used in conventional optical holography, so its whole process including recording, storage and reconstruction is digitally realized. Digital holography has been attracting intensive research efforts during recent years due to its potentials in automated high-resolution deformation measurement and shape analysis, microscopic imaging and testing, particle size analysis, as well as encryption of information and display, etc. Studying the methods of eliminating the zero-order diffraction and conjugate images and improving digital holographic imaging quality are of great importance.In this paper, the fundamental and the method of digital holography were analysised. A novel method for reconstructing object wave-front from a single digital Fresnel off-axis hologram is studied importantly. Based on theoretic analysis, computer simulation and the optical experiment research; this paper gives some analyses about the fundamental issue of digital holography including recording sampling requirement, reconstructing separation condition. Its application in microscopy is studied, some results are obtained, some reasonable explain for the experimental results are given. The main work and innovative ideas in this paper are as following1. The principle and fundamental methods of digital holography is analyzed, such as recording sampling requirement, reconstructing separation condition, imaging resolution, etc.2. The method for reconstructing object wave-front from a single digital Fresnel off-axis hologram based on the digital characteristic of CCD recording is studied, and the correctness and validity of this method are demonstrated with the results on both computer simulation and optical experiment. A new idea for obtaining real-time clear image of digital holograph was produced.3. By the comparison study of local algorithm of wave-front retrieval and Fourier transform spectrum filtering algorithm, the conditions of obtaining clear image about two methods were obtained.4. Some primary results by application of local method in micro-holography were obtained.