共查询到19条相似文献,搜索用时 343 毫秒
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单模光纤窄带波分复用器的研究 总被引:1,自引:0,他引:1
由组合波导理论出发,分析了超长耦合器合区光纤间的功率耦合特性以及器件的偏振特性,并提出了研制二段窄波分单模光纤波发复用器的新方法,在研制常规耦合器的工艺基础上,先后研制成功1310nm或1550nm单窗口窄带波分复用器及1310nm或1550nm双窗口等三种复用间隔约14nm的窄带波分复用器,其波长隔离度大于20dB,具有2~3nm的带宽,偏振灵敏度小于0.1dB,附加损耗小于0.5dB,这些参数 相似文献
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四通道实时联合变换相关器 总被引:2,自引:0,他引:2
提出把光学波阵面分割复用器用于单通道实时光电混合联合变换相关系统实现四通道实时相关,使单通道系统扩展为具有多个独立通道的系统,使系统的容量和处理速度提高数倍,使系统的性能得以改善。给出了新系统的设计方案、工作原理和实验结果。 相似文献
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阵列波导光栅设计原及优化 总被引:1,自引:0,他引:1
本文从波导光学和衍射光学理论出发,推导出阵列波导光栅(Arrayed-Waveguide Gratings)型波分复用器的重要结构参量;针对其性能参量,提出了一些优化设计方法。 相似文献
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阵列波导光栅设计原理及优化 总被引:5,自引:3,他引:2
本文从波导光学和衍射光学理论出发,推导出阵列波导光栅(Arrayed-Waveguide Gratings)型波分复用器的重要结构参量;针对其性能参量,提出了一些优化设计方法. 相似文献
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光纤马赫—陈德尔干涉型8波分超窄波分复用器的研制 总被引:9,自引:2,他引:7
报道了采用7个单模光纤马赫-陈德尔干涉仪进行三级串联而组成的8波分复用器,既保留了干涉型光纤波分复用器超窄波分复用间隔的优点,又消除了其复用路数少的缺点。文中介绍了这类波分复用器的原理、设计方法和制造技术。实验样品的使用波段为1.5μm,波长复用间隔为2.4nm,整个器件的附加损耗约为1.5dB。 相似文献
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波分复用器(WDM)作为光纤通信中一种重要的元器件,能够在不改变原有通信线路的条件下,有效地增加光纤通信的容量。传统的波分复用器主要基于色散原理,分光比不能准确控制,信号间串音大;而基于平面波导中多模干涉效应研制的波分复用器,具有体积小,损耗低(<05dB),不受光偏振态的影响,易集成等优点;在很宽的工作波长范围内,受环境变化影响小,适合现代通信器件集成化的发展。利用多模干涉效应(MMI)集成的098μm/155μm波分复用器,波导长度仅几个毫米,分光比例准确,隔离度可达30-40dB,波形失真小,它不仅可用于155μm光纤激光器和EDFA的集成,也可用于实现1×N和N×N分光,在光纤通信中有广泛的应用前景。 相似文献
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Multitarget detection using a hybrid optical joint transform correlator with power spectrum subtraction is proposed. This architecture is a programmable single spatial light modulator joint transform correlator. It consists of a liquid crystal display panel, an imaging lens, and a liquid crystal light valve to enhance resolution and space-bandwidth production. In this technique, it has two joint images in the input plane. In the second joint image, the reference image is contrast-reversal. With this technique, the second joint power spectrum is subtracted from the first joint power spectrum and the subtracted joint power spectrum is then taken the inverse Fourier transform. This technique is found to yield better correlation output performance than that of the classical joint transform correlator. Computer simulation results and the optical experimental results for input scene of the multitarget are given.The results have verified the correctness of the system design and performance analysis. 相似文献
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1IntroductionFormultitargetdetection,thejointtransformcorelator(JTC)isanextremelyusefularchitecture[1].HowevertheclasicalJTCp... 相似文献
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修正振幅调制的光电混合圆谐联合变换相关器作旋转不变的目标检测 总被引:1,自引:0,他引:1
提出一种修正振幅调制的光电混合圆谐联合变换相关器作旋转不变的目标检测的实验系统。参考图像(即圆谐展开分量的实部和虚部)、圆盘状的局部偏置函数以及目标图像同时显示于输入面。此方法对联合功率谱作了修正,先将联合功率谱减去纯输入景物(含局部偏置函数)的功率谱和参考图像(含局部偏置函数)的功率谱,再加上局部偏置函数的功率谱,然后将所得修正的联合功率谱乘以振幅调制滤波函数。这种方法能产生比普通的圆谐联合变换 相似文献
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HUANG Xiaojing 《Chinese Journal of Lasers》1999,8(1):49-54
1IntroductionForrotationinvariantpaternrecognition,thespatialmatchedcorelatorisoftenusedbytakingacircularharmoniccomponent(CH... 相似文献
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In order to utilize the space of an input plane efficiently and make the optical structure more flexible, an image displacement measurement based on phase-encoded reference joint fractional transform correlator (PER-JFrTC) is proposed. We use a random phase mask to encode the reference image and overlay it with the target image forming the input image. Joint power spectrum (JPS) of the input image is obtained by Fourier transform and the resultant is encoded by the same phase mask. Then a fractional Fourier transform with an order p is applied to the phase-encoded JPS (PJPS), resulting in a correlation output with a sharp cross-correlation peak, which includes the displacement information between the reference and the target image. Contrast to displacement measurement based on traditional joint transform correlator (JTC), PER-JFrTC can use the space of the input plane efficiently and reduces the influence of the auto-correlation. Also the position of cross-correlation peak can be fixed arbitrarily according to the fractional order p as well as the optical set-up can be more flexible and easier to implement. Results based on digital computation show that PER-JFrTC could detect the displacement accurately and verify our proposal. A possible optical set-up is suggested. 相似文献
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实时光电混合联合变换相关器单元的实验研究 总被引:11,自引:3,他引:8
本文根据联合变换相关的原理,提出了一种实时光电混合联合变换相关器,它采用一个液晶光阀作为输入器件,用另一个液晶光阀记录和显示联合功率谱,所给出的实验结果证实了该系统设计及性能分析的正确性。 相似文献
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In this paper two new architectures for optical image verification are proposed. Both architectures are based on conventional joint transform correlators (JTCs) adopting a Fourier hologram and can significantly improve the recovered image quality. First, an input phase-only function is Fourier transformed and then interferes with a reference wave that is diffracted from a plane wave incident on another random phase mask. Second, two phase-only functions are placed at the two input sides of a beamsplitter such that the interference pattern of their Fourier transforms can be detected. To obtain a predefined target image in the output plane, one of the input phase functions is iteratively retrieved by the use of the projection onto constraint sets algorithm. Simulation results show that the less mean squared error and better image quality are obtained for both the binary and grayscale images. 相似文献
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提出了用联合变换相关器(JTC)来实现证据理论概率分配函数正交和的光学计算,在理论上对于如何用联合变像相关器实现证据理论分配函数正交和作了详细的讨论,并作了相应的仿真测试,结果显示该方法是可行的。与John Caulfield提出的用声光器件矢量外积实现的正交和计算相比,在该结构中由于采用二进制编码的数值计算,因此其计算精度得到了提高,同时对联合变换相关器输入端二进制编码的数值空间位置的适当调整可以直接得到所需要的证据理论正交和矢量,在处理步骤上得到了简化。 相似文献
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新型平面集成光学相关器设计与分析 总被引:2,自引:2,他引:0
基于微光学与二元光学技术,设计了一种新型的平面折叠式光学相关器,将相关器中组成4f系统的傅里叶变换透镜、全息匹配滤波器、输入面和输出集成到一个平面器件上,与另一平面偏振反射镜构成一个反射型的平面光学系统.讨论了相关器的系统结构设计、系统参数的设计,给出了具体的设计模型,计算出其体积可减小至约12 cm3.利用菲涅耳衍射数值模拟方法对系统的图像识别过程进行了仿真,得到了良好的相关输出结果,证实平面集成光学相关器具有很好的识别性能. 相似文献