液晶空间光调制器的衍射特性及应用研究

发布时间：2018-01-24 10:21

本文关键词： 液晶空间光调制器波长选择开关纯相位调制闪耀光栅　出处：《北京交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着密集波分复用(DWDM)技术的广泛应用和光纤传输容量的巨幅增长,SDH技术早已不堪重负,以波长选择开关(WSS)为基础的第三代多功能可重构光分插复用器(ROADM)作为实现下一代动态全光网络的关键设备,在近年来受到了光通信领域研究机构的高度重视,并得到了快速发展。而基于液晶空间光调制器(LC-SLM)的WSS具有波长无关(Colorless,各上下路端口均可重构至任意波长)、方向无关(Directionless,各上下路端口均可重构至任意方向)、无竞争性(Contentionless,可灵活上下路不同方向的同一波长)、高度光谱灵活性等特点成为了现今国内外研究的重点。本文在对纯相位液晶空间光调制器衍射特性进行理论分析与数值仿真研究的基础上,采用简洁的光学系统设计研制成功了一种基于液晶的波长选择开关实验原型。具体开展的工作如下： (1)简要介绍了液晶空间光调制器的发展,从液晶材料的电光特性出发,研究了液晶分子对光波的调制原理和液晶空间光调制器的基本结构,并利用琼斯矩阵理论分析了偏振光经过液晶调制后的偏振态和光强的改变。 (2)利用标量衍射理论建立了液晶空间光调制器加载闪耀光栅图像时衍射效率的分析模型,分别用空间域和频率域的方法推导出衍射效率的计算公式,并运用MATLAB软件模拟了衍射光强曲线。 (3)用泰曼一格林干涉装置来测量液晶空间光调制器的相位调制特性,通过MATLAB编程进行图像处理并计算得到了每个灰度值对应的相位延迟量,绘制出相位调制特性曲线。通过分析计算,校正了相位调制特性曲线,提高了液晶的衍射效率。 (4)在理论分析的基础上,搭建了基于液晶的波长选择开关(WSS)实验平台,实现了支持灵活光谱的1×30端口的WSS基本功能。使用JAVA语言为液晶空间光调制器编写相应的控制软件,为进一步开展波长选择开关实验样机的研制提供了理论基础和关键技术支撑。
[Abstract]:With the wide application of DWDM (dense wavelength Division Multiplexing) technology and the huge increase of fiber transmission capacity, SDH technology has already been overwhelmed. The third generation multifunctional reconfigurable optical add / drop multiplexer (ROADM) based on wavelength selective switch (WSS) is the key device to realize the next generation dynamic all-optical network. In recent years, it has been attached great importance by the research institutions in the field of optical communication. The WSS based on liquid crystal spatial light modulator (LC-SLM) has wavelength independent colorless, and the upper and lower ports can be reconstructed to arbitrary wavelength. Direction has nothing to do with Directionless, each upper and lower ports can be reconstructed to any direction, no competitive Contentionless. The characteristics of flexible upper and lower paths in the same wavelength and high spectral flexibility have become the focus of research both at home and abroad. Based on the theoretical analysis and numerical simulation of the diffraction characteristics of the pure phase liquid crystal spatial light modulator. An experimental prototype of wavelength selective switch based on liquid crystal has been designed and developed by using simple optical system. The detailed work is as follows: 1) the development of liquid crystal spatial light modulator is briefly introduced. Based on the electro-optic characteristics of liquid crystal materials, the principle of liquid crystal molecular modulation of light wave and the basic structure of liquid crystal spatial light modulator are studied. The polarization state and the change of light intensity of polarized light after liquid crystal modulation are analyzed by Jones matrix theory. (2) using scalar diffraction theory, the diffraction efficiency analysis model of liquid crystal spatial light modulator loaded with blazed grating image is established, and the calculation formulas of diffraction efficiency are derived by the methods of spatial domain and frequency domain, respectively. The diffraction intensity curve is simulated by MATLAB software. The phase modulation characteristics of liquid crystal spatial light modulator are measured by using Tymann-Green interferometer, and the phase delay corresponding to each gray value is calculated by MATLAB programming. The phase modulation characteristic curve is drawn, and the phase modulation characteristic curve is corrected through analysis and calculation, which improves the diffraction efficiency of liquid crystal. On the basis of theoretical analysis, an experimental platform of wavelength selective switch (WSS) based on liquid crystal is built. The basic function of 1 脳 30 port WSS supporting flexible spectrum is realized, and the corresponding control software is written in JAVA language for liquid crystal spatial light modulator. It provides the theoretical foundation and key technical support for further developing the experimental prototype of wavelength selective switch.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN761

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