【作者】 曹星烨；

【导师】 刘向东； 郑臻荣； 李海峰；

【作者基本信息】 浙江大学 ， 光学工程， 2008， 硕士

【摘要】 光学滤光片用于从一个二维图像的连续的光谱中提取一定宽度的光谱带,滤光器的早期目的是用于天文观测。可调谐滤光片则是使得滤光片的通带可以根据需要进行调节,是滤光片系统的重要发展。随着光谱学的发展,可调谐滤光片作为光谱分析的重要工具,被广泛应用于物理化学、生物医学、远程探测、军事侦查等研究领域。其中,双折射干涉滤光片由于原理简单,且具有光谱性能好,生产装配简易等优点,并且能够利用电控液晶实现可调谐,因而被各国广泛深入的研究。本论文的目标是设计并制作能够在整个可见光谱实现波段可调窄带滤光的滤光片。本文第一部分主要介绍了各种滤光器件的原理与结构。其中,对可调谐双折射滤光片进行了深入的探讨,包括Lyot与Solc两种主要的双折射滤光片系统结构,以及机械转动调制、电控液晶调制这两种主要的可调谐实现方式。经过比较,根据几种系统的优缺点以及本所的技术基础,采用了装配较为简单的液晶可调谐Lyot滤光片作为课题研究方向。第二部分为多级液晶可调谐Lyot型滤光片的设计。主要包括光学部分的设计和驱动电路的设计。首先是光学部分的设计,提出了最大化利用液晶盒双折射能力以提高光谱分辨能力的方案,并实际设计了六级式液晶可调谐Lyot滤光片,使用软件进行了模拟。其次介绍为了实现多级液晶可调谐滤光片的可程控调谐,而设计制作的以单片机和多路数模转换芯片为核心的驱动电路。第三部分是系统的装配和测试。首先介绍了六个单级液晶可调谐Lyot滤光片的制作,给出了测试结果,并对测试结果进行了分析,得到了液晶盒电控双折射的特性;其次将装配的六级液晶可调谐Lyot滤光片进行了测试,并阐述了使用硅油提高系统透过率的方法,通过实验证明了该方法的有效性。最后对工作进行了总结,并对该系统的进一步改进提出了方向。更多还原

【Abstract】 Optical filters are spectrum instruments which are used to intercept specified spectrum information from the continuous spectrum of a 2-D image. In early period, Optical filter was used in astronomic observation. But as developments took place in spectrum science, optical filters have been used in physics, chemistry, biomedical, remote sensing, military scouting, as important spectrum instruments. Birefringence interference filters (BIFs) have been given considerable attention by researching institutes in many countries, due to the advantages in simple principle, excellence spectrum performance and simple assembling. BIFs have been researched deeply in Europe and U.S, and products were developed and employed. But the researches in BIF haven’t gone far enough in China. This paper is to design and assemble a tunable narrow band BIF which can work in whole visible spectrum.The first part of this paper introduces the principles and structures of kinds of optical filters. Tunable BIF systems were thoroughly introduced, including the Lyot type BIF and Sole type BIF. Tuning methods were also introduced, including mechanical rotating method and liquid crystal (LC) electronic controlling method. After comparison of these systems, and according to our school’s technical foundation in LC research, LC based Lyot type tunable filter system was adopted because of its simplicity in assembling.The second part introduces the designing of this system, including optical elements designing and electronic circuit designing. In optical designing, a method was carried out aiming to make most use of LC birefringence to achieve best spectrum resolution performance. A six-stage Lyot tunable BIF was designed using this method, and was emulated by software. A circuit was design to achieve the ability of program controllable tuning, the main parts of this circuit are microcontroller and multi-way D/A converter.The third part introduces the assembling and testing of this system. Firstly, the assembling of six single-stage Lyot tunable BIFs is introduced, and experiment results were given. The results were analyzed, and the LC birefringence characteristic was achieved. Second, the six-stage Lyot tunable BIF was assembled and tested. A method using silicon oil to improve the system’s transmission performance was introduced, and was proved by experiment.Finally, the whole work is summarized, and further improving direction was given.更多还原