液晶技术用于计算机光学元件的研究

【作者】 荆汝宏；

【导师】 黄子强；

【作者基本信息】 电子科技大学 ， 光学工程， 2010， 硕士

【摘要】 激光束横向光强分布为高斯分布,在应用过程中经常要对其横向光强分布加以变换。目前多用计算机光学元件(computer optical elements)来实现这种变换过程。计算机光学元件能够产生任意形状的波面分布,且衍射效率较高,然而其制作工艺复杂,加工设备比较昂贵,这就限制了元件的应用范围。论文以激光光束整形为切入点,从一个新的角度进行探索,尝试用液晶技术来实现计算机光学元件的功能。论文主要涉及到计算机光学元件的研究概况、所用的设计理论、加工方法,另外还包括液晶技术实现该类元件的基本原理及实现方法,黑栅效应的理论分析等几个方面。论文首先用几何设计理论设计出将激光光束整形为一个均匀正方形光斑、两个均匀椭圆形光斑的光学元件,用MATLAB7.1软件进行了模拟,得到了预期的结果。另外还研究了影响整形效果的各个参数,并进行了实验验证。随后,最为对比,用标量衍射理论重新设计了上述计算机光学元件,主要是采用G-S算法,对该算法进行了相应的优化后,其运算速度提高了近15%。通过上述的设计过程,分析了两种理论的优缺点,对计算机光学元件的设计有了较深的理解。最后重点介绍了液晶技术实现计算机光学元件的基本原理,并做了用液晶技术实现上述光学整形元件功能的实验验证,分析了影响整形效果的因素。在验证过程中,深入研究了黑栅效应,建立了黑栅效应的理论模型,用傅里叶光学的理论对黑栅效应进行了分析。为了定量分析黑栅效应对整形结果的干扰,用MATLAB7.1软件进行了模拟,并在此基础上提出了减小黑栅效应干扰的措施。更多还原

【Abstract】 The transverse intensity distributing of laser beam is gaussian distribution, in actual application, the distribution often need to be reshaped. Now Computer Optical Elements (COES) are used to realize this function. This kind of elements can generate arbitrary shape of wave surface theoretically and their average diffraction efficiency are very high, but the manufacturing processes of elements are so complicated that the application scope of them is restricted.In this dissertation, laser beam shaping is selected as the breakthrough point, and liquid technology is used to realize the function of COES. The design theory, manufacture methods of COES, the liquid technology to realize COES, and the theoretical analysis of black matrix effect are studied deeply.Firstly, two kinds of simple elements which reshape the laser beam to one flat square and two flat ellipses are designed using geometric theory, at the same time, the design results are simulated using MATLAB7.1 .Then, the elements mentioned above are designed again using scalar diffractive theory for comparison, during this process, G-S algorithm is used and optimized. After the optimization the calculation speed is increased almost 15% . In this part , two design theories of COES are studied deeply, and the advantages and disadvantages of two theories are analyzed.Finally, the basic principle of realizing COES using liquid technology is introduced, some experiments are conducted to verify the theory, at the same time, a few factors that influence the imaging effect are analyzed. During this process, black matrix effect is studied intensely, then the black matrix effect is analyzed using Fourier optics. In order to know the black matrix effect vividly, the interference of the effect is simulated using MATLAB7.1, according to the simulation results, some measures that can be used to reduce the interference of black matrix effect are put forward.更多还原