The Recording and Reconstruction Technology of Digital Holography
|School||Changchun University of Science and Technology|
|Keywords||digital holography CCD EALCD space bandwidth product Laplacianoperator|
With the progress of science and technology, industrial requirements increase, measuring precision about displacement and deformation becomes higher and higher.Measurement accuracy of digital holographic measure technology has easily up to micron level. And it has many advantages, such as full-field, real-time, non-contact, high-contrast. Therefore, it has big trend in the development of holographic interferometry. In this paper, holographic interference measure system based on photosensitive detector,EALCDand CCD,has been designed. And puts forward the key technology of digitalholography based on theories and experiments.paper covered the theory knowledge and practice, and many issues on the system have been studied in detail, such as theoretical research、experimental conditions、equipment selection、optical path design、optical assembling and adjusting、the image processing. Some practical research results have been Obtaine.For the realization of the digital holographic interferometry, the key technology of digital hologram have to be soloved. It means that the system shall meet the following requirements:temporal coherency, spacial coherency, space bandwidth product, light polarization degree, the contrast of fringes, resolution conditions and distance conditions. But through light path, the recording of hologram will be affected by various factors, For example, instrument error, optical adjusment is not enough precise, stray light, surrounding environment is not stable and so on,which makes the hologram inevitably contains noise. To raise the quality of representation, sharpening and a series of processing must be adopted.so Laplace image processing method which an effective way to improve the holographic representation and holographic interferograms contrast has been putted forward.