Matlab-based Digital Microscopy Holographic Image Emersion

Digital holography has adopted the photovoltaic conversion equipment in place of chemical sensitive record medium and used computer to simulate reconstructive image, and consequently has various advantages than traditional optical holography. That it was wide concerned. Digital holographic microscopy, a new microscopy, was developed from the digital holography. The paper firstly analyses and discusses the principle of recording and reconstruction of the digital holography, numerical reconstruction algorithm, frequency filtering method, the recording method of digital hologram, the separate conditions of reconstructive amplitude. Then takes the following research:1. Based on classic holographic microscope for transmission imaging and planar reference light designed the basic parameters of the holographic reconstructive of program: the wavelengths of the lamp-house is 633nm, the reference light is planar reference light and its bias degree is 0.03, the record distance is 35mm, choose CCD to be record medium.2. Simulate rectangle phase grating as detection objects, and the grating parameters is the same as CCD's. The size of the grating is 1024×1024 pixels, and the size of each pixel unit is 4. 65μm×4.65μm. The cycle of the grating is 8 pixels.3. Based on the Fresnel approximation algorithm compiled program to reconstruct holographic image and test the correctness of the program. Firstly the program simulate record the hologram of the grating, then numerical reconstruct holographic image. The result of reconstruction fundamental to achieve the expected target.4. Discusses the error of the reconstruction, and make a hypothesis that the error comes from the algorithm and validate the hypothesis. Respectively simulate two grating that cycles are 16 pixels and 32 pixels, and record hologram and reconstruct holographic image with them. Contrast the thrice results and final conclusion, for detection object the big microcosmic configuration the high reconstructive precision.5. Validate the absoluteness which record distance affects reconstructive precision. Only when the record distance equal to reconstruct distance can get the best result.