【作者】 江益；

【导师】 姚端正； 曾立波；

【作者基本信息】 武汉大学 ， 光学， 2005， 硕士

【摘要】 声光可调滤波器（AOTF）是根据声光作用原理制成的新型分光器件,它具有传统分光元件（棱镜或光栅）不能相比的优点,主要包括体积小,全固体构件,无运动部件;通光孔径大,入射角孔径大:衍射效率高;电调谐,扫描速度快等。目前,利用AOTF开发的各种光谱仪已经应用在工业、农业、航空等领域,取得了良好的效果。由于有较大的通光孔径和入射角孔径,AOTF在成像光谱的应用领域有着很大的潜力,但由于TeO₂材料的色散造成的图像漂移和模糊问题,阻碍了应用的发展。本论文通过对AOTF参数的精确计算以及对晶体出射面添加精心设计的光锲,在理论上解决了传统的AOTF图像漂移和成像模糊的难题。数据模拟和定量计算的结果表明,采用本论文所用方法,可以基本消除掉图像漂移现象,并能提高图像的清晰度分辨率。基于本论文设计的AOTF,并整合光学元件、成像镜头,CCD探测器、射频电源本论文还设计并实现了光谱成像系统。系统在计算机的控制下进行光谱波段扫描,光谱图像采集功能。对系统在光谱扫描精度、光谱分辨率、图像漂移、图像质量方面的性能进行测试都得到了良好的结果。利用该系统对的植物树叶的成像光谱分析验证了绿色植物的“红边”现象。而首次对草地蝗虫模拟环境的实验,发现了在近红外蝗虫和草地反射光谱的巨大差异。这也标识了该系统在农业病虫害检测领域的巨大应用前景。更多还原

【Abstract】 Acousto-optic tunable filter （AOTF） is a newly developed spectroscopic device based on acousto-optic interaction. Compared with the traditional spectroscopic components （prism or grating）, it has a lot advantages, including small bulk, solid state and no moving parts; large light and angle aperture; high diffraction efficiency; fast electrical tuning speed and so on. Up to now the application of AOTF is spreading to the fields of industry, medical care, remote sensing and scientific researching, and all the applications have made favorable effects.Because of the large light and angle aperture, AOTF has quite wide potential in spectral imaging field. While since the TeO₂ has natural dispersion, it will cause scene shift and imaging blur, and hence hinder the application in imaging field.This article precisely calculates the parameters of AOTF and adds a precisely designed wedge to produce the chromatic correction with its natural dispersion. The results of numerical simulation prove this method can correct the scene shift totally and improve the spatial resolution greatly.Base on the dispersion removing AOTF design in this article, and integrating optical elements, imaging lens, CCD detector and RF power, we designed and implement a spectral imaging system. With the computer control, it can realize spectral scanning and spectral imaging collecting. The test result of spectral wavelength accuracy, spectral resolution, scene shift, imaging quality for this system is satisfactory. Using this spectral imaging system, we first study plant leaf, and verified the leaf’s "red edge" phenomena. And then in the experiment of locust and grass environment spectral imaging analysis, we found the reflecting rate of locust and grass differ greatly in NIR, and this trait have a great potential application in the field of agriculture insects monitoring.更多还原