【作者】 李显利；

【导师】 田逢春；

【作者基本信息】 重庆大学 ， 信号与信息处理， 2010， 硕士

【摘要】 光学信息系统具有并行处理信息的优势,其速度远高于电子计算机的处理速度,但它一直受光学器件的技术和精度制约,系统存在相干噪声大、稳定性差、调节困难等缺点,因而导致信息光学技术在高精度处理方面多年来发展缓慢。近年来涌现的新技术使相干光信息处理系统取得突破性的进展成为可能。其一,具有高精度、高分辨率的纯相位光学调制器面世使得调节相干光的波前相位成为可能,由此可真正实现全光并行负反馈系统。其二,大截面光纤传像束和基于三维MEMS(微机电系统)技术的光交叉连接器问世,可实现参数可调的集成仿射线性变换并进而实现二维图像迭代函数系统(IFS)。首先,论文从原有的光学反馈系统出发,分析了二维光学负反馈实现的可能,构建了基本的光学负反馈系统。其次,讨论了两种特殊的迭代函数系统,提出了用光学方法实现迭代函数系统的思想,图像迭代函数系统从本质上说是一个二维反馈系统,通过全光实现二维迭代函数系统,可以提高系统抗干扰能力和计算速度。再次,进行了常见光学仿射变换实验,鉴于实验具有调节困难、精度低、灵活性差和稳定性差等缺点,本文提出了基于光纤传像束和MEMS(微机电系统)光交叉连接的方法,通过利用MEMS光交叉连接可以实现任意端口间的交换特性,与光纤传像束结合能够用光学方法实现任意仿射变换。克服了上述问题。光学实验与数字仿真实验的对比有力地证实了该方法的优越性。随着大截面光纤传像束和MEMS技术的光交叉连接的进一步发展,有望提高并行图像处理系统的速度、精度、稳定性等方面获得突破。目前用光纤传像束和MEMS光交叉连接实现任意仿射变换还存在分辨率不够高和对图像离散化等问题,我们可以利用透镜组实现缩放来提高分辨率,但灵活性稍差。因此,在提高系统分辨率方面还值得深入研究,以进一步提高系统精度。更多还原

【Abstract】 Optical information processing has the advantage of high-speed parallel processing. Its processing speed is much faster than that of computer. but it has been restricted by current technology and precision of optical devices, so the system has high coherent noise, poor stability, adjustment difficulties and other shortcomings, which results in the slow development of information processing in high-precision optical technology over the past decades. In recent years a great breakthrough is possible for the emergence of new technology to achieve coherent optical information processing system. First, phase spatial light modulator with high precision and high-resolution made adjustable coherent light phase wavefront possible, thus can realize all-optical parallel negative feedback system. Second, the emergence of optical cross-connect for large cross-section optical fiber image bundle and MEMS technology can realize arbitrary affine transform in optics. Ultimately image iterated function system(IFS) can be obtained.First of all, according to the existing optical feedback system, the two-dimensional optical negative feedback was analyzed, and a basic optical negative feedback system is constructed. Secondly, two specific iterated function systems were discussed, and an optical iterated function system is a two-dimensional feedback system. Through all-optical realization of two-dimensional iterated function systems, this can improve anti-jamming capabilities and the computing speed. Thirdly, conventional optical affine transform is implemented, with the shortage of experimental adjustment difficulties, low accuracy, poor flexibility and stability. A method for optical affine transform based on optical fiber bundle and MEMS (Micro-Electromechanical Systems) optical cross-connect is proposed. An arbitrary optical affine transform is realized by making use of the switch property of MEMS combined with optical fiber bundle. The shortcomings of traditional methods can be overcome effectively by this way. Comparison of optical experiment results and simulation results proves the superiority of this method. With further development of the technology of large cross-section fiber-optic image bundles and MEMS optical cross-connect, parallel image processing system is expected to achieve breakthrough in speed, precision and stability, etc.Currently, the optical affine transform realized by the combination of optical cross-connection based on MEMS with optical fiber bundles has many problems such as the low resolution. As to discrete graphics, we can use lens group to achieve zoom which can improve the resolution, but it results in somewhat less flexibility. So the way to improve system resolution deserves studying to improve the precision system.更多还原