【作者】 席庆奎；

【导师】 陈进榜； 朱日宏；

【作者基本信息】 南京理工大学 ， 光学工程， 2007， 博士

【摘要】 计算全息因为可产生任意形状的衍射波前,已广泛用于光学实验与计量。但由于存在不能实时实现的弱点,许多学者用现代显示器件(如液晶板等)进行了计算全息实时应用研究,如:光学联合变换滤波器图像识别技术,实时计算全息干涉防伪技术,傅里叶变换实时全息图应用。实时计算全息技术已成为当前的研究热点、新兴领域。由于液晶板等现代显示器件的离散性结构和制造工艺误差,以及计算全息设计原因,如图案失真误差和液晶板基板外形误差等,使得计算全息再现的衍射波前出现误差。本文针对这些问题,围绕实时应用计算全息主题,在以下几个方面进行了研究。根据计算全息理论,采用液晶板、数字微镜等现代光学显示器件,实时显示计算全息图,并成功用于多种光学实验,建立了计算全息实时应用的技术方法。研究了实时计算全息的误差问题,包括图案失真误差、液晶板基板外形误差和频宽比误差。通过实验,分别记录了零级和一级衍射光的波前位相灵敏度随光栅变化的规律,得到与理论值相一致的结论。研究了液晶板与数字微镜器件的结构、工作原理、光学传播特性及位相、振幅调制特性,设计与建立了测量液晶板输出波面位相、振幅等参量的实验系统,得到了有关实验数据,为实时控制液晶板建立了基础。运用实时计算全息技术,采用液晶板,实时产生了球面、螺旋面波前,经与胶片记录的计算全息图对应比较,其结果良好;并进行了实时计算全息测量非球面的实验。探讨了液晶板、数字微镜产生实时计算全息的应用研究,研究了实时计算全息用于球面、非球面的朗契检验方法;研究了实时计算全息作为扫描显微镜的光束扫描器,改善了显微镜的性能。更多还原

【Abstract】 Computer-generated holograms (CGH) are widely used in optical testing and metrology, as the CGH is capable of producing diffractive wavefront with any desired shape. Since CGH is not real-time available, many scholars are studying the real-time applications of CGH with modern display devices, such as liquid crystal display(LCD), The applications include, real-time pattern recognition using liquid crystal display based joint transform correlator, CGH interferometric technology for anti-counterfeiting, and real-time application of Furrier transform CGH. Now, real-time CGH is becoming a study focus. The discrete structure of LCD, errors of the hologram fabrication processes and design of CGH, such as pattern distortion and substrate figure errors of LCD, cause errors in the re-constructed diffractive wavefront. This dissertation studies on these errors and real-time application of computer-generated holograms are studied in several respects.According to the theory of computer-generated holograms, using modern optical display devices, such as liquid crystal display and digital micromirror device(DMD), computer-generated holograms are shown real-time, and are used in several optical experiments. Errors of the real-time computer-generated holograms, including substrate figure errors and pattern distortion, are discussed. By experiment, the change of wavefront sensitivity functions of zero- and first-order diffraction beam is tested. In the mean time, experimental result is compared with theory data, with the two agreeing well. The construction and work mechanism of the liquid crystal display and DMD, the characteristic of optics transmission and phase or amplitude modem are studied. The experiment system to detect phase and amplitude of output wavefront is designed, and used to do experiment, setting up the base of controlling LCD real-time. On the theory of real-time CGH, using LCD, spherical and helical wavefronts are produced real-time, and compared with wavefront whose CGH is recorded by film. An aspheric is tested with real-time CGH. The application of the real-time CGH using LCD and DMD as record substrate is studied, such as testing sphere or aspheric by Ronchi test with real-time CGH. And light beam scanner of scanning microscope is made with real-time CGH, improving the property of scanning microscope.更多还原