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	Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文 OAI收割 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China 作者: Zhang J.; Zhang J.; Zhang J.; Shi G.; Zhang X. 收藏 \| 浏览/下载：25/0 \| 提交时间：2013/03/25 Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus which means the system MTF is quite insensitive to defocus and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.
	The effect on tolerance distributing of an off-axis three mirror anastigmatic optical system with wavefront coding technology (EI CONFERENCE) 会议论文 OAI收割 Optical System Alignment and Tolerancing II, August 10, 2008 - August 11, 2008, San Diego, CA, United states 作者: Yan F.; Zhang X.-J.; Yan F. 收藏 \| 浏览/下载：35/0 \| 提交时间：2013/03/25 The wavefront coding technology is known as a system-level technology which can extend the depth of focus of optical system by innovative optical design and image restoration. This technology can control misfocus related aberrations including misfocus astigmatism and Petzval curvature temperature-related misfocus in digital imaging systems. It can also help optical system tolerate more residual error in optical manufacturing and alignment besides misfocus. The brief introduction of wavefront coding technology and the wavefront coded TMA system under research is presented respectively in part 1 and part 2. The "MTF similarity" is defined to describe the relationship among MTF at different position or different fields in the third part. It is also shown in this part that the MTF similarity of wavefront coded system is much higher than the normal system within a large range. In part 4 comparison between the origin system and the new system with wavefront coding technology is provided after multiple errors are introduced from which it can be observed that the system with wavefront coding technology can tolerate much bigger error than origin system. The error tolerance is re-distributed according to a new criterion based on MTF similarity. If the MTF similarity is less than a certain value it can be regarded that the system can tolerate the residual error. The new error tolerance is displayed and it is shown that the wavefront coding technology can also loosen the error distributing besides extended the depth of focus.
	扫频光学相干层析成像技术研究学位论文 OAI收割作者: 王瑄 \| 收藏 \| 浏览/下载：72/0 \| 提交时间：2018/12/26 扫频光学相干层析成像 swept source optical coherence tomography 灵敏度 sensitivity 焦深 depth of focus 波数校准 wavenumber calibration 成像深度范围 imaging depth range