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光子学报 1998
NOISE ANALYSIS FOR THE IMAGING SYSTEM THROUGH SCATTERING MEDIUM USING ULTRASHORT PULSE LASER ELECTRONIC HOLOGRAPHY
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Abstract:
In this article,noises of the imaging system through scattering medium using ultrashort pulse-laser electronic holography is analyzed in detail.The main noise sources are the recording and reconstructing processes of electronic holograms,and the noise of CCD camera and optical system components.In the recording process,there are white noise produced from later-arriving-light and noise from the shoulder of fs laser-pulse,multiple reflections of reference light,unstable optical system and scattering medium.Besides,if the fringes of holograms are not straight and vertical,or the angle between object and reference light is too small,it is possible that noise is produced.In reconstructing process,the overlap between +1 order and 0 order of spatialfrequency spectrum of holograms is a main reason for noise.CCD camera noise includes thermal noise,shot noise,sensitivity variation, sampling error etc.Also dust and the defect of optical system components can produce noise.The relevant processing measures of all noises are put forward.