两维局域互联神经网络的关联存储

本文将局域互联神经网络的新概念推广到两维情形,并对两维局域互联关联存储进行了理论分析和大量的计算机模拟.结果表明,两维局域互联神经网络的优点是,在满足存储容量限制的前提下,它与全局互联神经网络具有相同的关联存储能力,而其互联权重矩阵要比全局互联网络小得多.因而,有利于使用现有的空间光调制器实现两维大规模的人工神经网络.     

A module design of rearrangeable nonblocking double omega optical network using binary optics elements

Omega network plays an important role in all optical communication and optical interconnection networks. In this paper, a novel technology, which binary optics element (micro-blazed grating array) can realize perfect shuffle transform including inverse perfect shuffle and left perfect shuffle, is proposed. Moreover, by a cascade of inverse perfect shuffle and left perfect shuffle, a multistage rearrangeable nonblocking omega network can be constructed. Simultaneously, the bipartition graph algorithm (BGA) is adopted to ascertain the state of node switch in each node stage (straight or crossover connection). At last, a module of the rearrangeable nonblocking omega network which is integrated with polarizing beam-splitter, half-wave plate, micro-blazed grating array, is presented. It can accomplish the functions of 8-channel signal beams’ sorting and switching without routing conflict and blocking, and has advantages of being compact in structure, easy to integrate, efficient in performance etc. Finally, both the theoretical analysis and the experimental result show that this module proposed here may be helpful in free-space optical interconnection network and optical information processing.     

PS~(-1) Optical Interconnection of 2N×2N Using N×N Holographic Lens Array

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PS-1 Optical Interconnection of 2N×2N Using N×N Holographic Lens Array

A method of N×N sub-array crisscross insertion has been put forward. N×N holographic lens array is used for realizing PS-1 optical interconnection of the 2N×2N element array. The condition for the sub-array interlacing was analyzed. The formula of the PS-1 imaging magnifying power and the imaging distance have been given for both parallel light illumination and divergent light illumination. The results indicated that the formula of the PS-1 imaging magnifying power and imaging distance realized by N×N sub-array crisscross insertion are identical with the results of the PS realized by 2×2 holographic lens array. The experiments prove correctness of the formula.     

用棱镜实现高效率的完全混洗互连网络

提出了用棱镜的普通光学系统实现二维的完全混洗互，连网络的新方法，方法简单，可行，可能有效地利用光能，因而具有实用意义。     

洗牌型图样间联想光学神经网络模型

本文将洗牌型神经网络结构和图样间联想神经网络算法相结合,提出了一种洗牌型图样间联想神经网络(PS-IPA)模型。该模型具有极其简单、稀疏的互连权矩阵,十分适于大规模神经网络的光学实现。计算机模拟结果表明洗牌型图样间联想神经网络的稳定性和抑制噪音的能力均优于图样间联想网络IPA.本文还给出了洗牌互连的一般性原则,使网络结构得到优化,增强了洗牌型神经网络的灵活性和适应性。并采用3-洗牌和2-洗牌结合的PS-IPA对汽车牌照的字符进行识别,得到了较好的结果。     

伸缩式全金属反射阵列扫描天线

提出了一种伸缩式全金属反射单元,在此基础上设计了一个可用于高功率微波领域的全金属反射阵列波束扫描天线。通过反射单元的上下独立滑动,阵列中每个阵元所接收电磁波的传输路径可改变,从而实现了相控波束扫描。由电磁仿真可知,设计的反射单元能够在10～13 GHz的频带范围内实现0～360°的线性相位调节,且可在15°～40°偏馈条件下相位调节时保持高功率容量。由该型单元组成的中心工作频率为10 GHz的伸缩式全金属反射阵列扫描天线具备90°锥角范围内的二维波束扫描能力,功率容量可达5 GW/m2。同时,在波束扫描过程中,天线增益变化小于3 dB,副瓣电平低于?13 dB,最大口径效率为54.59%。     

波长扫描干涉仪信号处理技术

Use 2×2 holographic lens array for realizing FPS optical interconnection. The derivation of all cases with parallel light incidence and the divergent light incidence indicated: the focus positions of the first and the third quadrants of the holographic lens array were related to the lens aperture and the number of input elements. The formulas of the imaging distance and system magnification of all the cases are in keeping with what the PS interconnection under the same condition.     

Study on FPS Optical Interconnection Realized by 2×2 Holographic lens Array

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Planar Radiating Oscillator Using Butterfly-Shaped Patch Element and Spatial Power-Combining Array

A planar radiating oscillator using a butterfly-shaped patch element is described. To obtain an injection-locking range that can be changed and low cross-polarization, we used a butterfly-shaped patch. The patch element was able to change the injection-locking range while maintaining low cross-polarization, and two types of patch were compared. As one application, we designed and fabricated 1x2, 2x1 and 2x2 spatial power-combining arrays by using radiative mutual coupling. The 2x2 array was successfully operated with a single-bias supply without using a 3-D (three-dimensional) Fabry-Perot cavity. An equivalent isotropic radiated power of 2.5 W was measured at X-band.     

基于衍射光学元件的全光分幅成像技术

超快成像技术可用于研究爆炸、高压放电等超快现象,其中,全光分幅成像技术可克服光电转换的时间限制,具有很大的发展前景。利用衍射光学元件和窄带滤波片搭建了全光空间分幅成像系统,成功实现阵列分幅成像,并分析了不同波段的成像效果。实验结果表明,所设计的全光空间分幅成像系统,可在不同波段内实现4×4阵列的16分幅成像;且图像幅间的非均匀性相对标准偏差为7.4%,幅内非均匀性均值为2.83%,全光分幅成像系统在分辨率为35 lp/mm时的调制传递函数为0.991。     

二维光学神经网络自由空间互连结构设计

本文分析了以透镜阵列元件建立空间互连通道的光学神经网络中神经元数的理论极限.为了提高网络中的神经元数,我们提出了一种并行结构设计,该结构克服了小透镜成象中的离轴象散的影响,提高了系统的光能利用效率,同时降低了系统中的对位精度误差,提高了互连运算精度.     

A two-way optical interconnection network using a single mode fiber array

We present a dynamic free space interconnection network for single mode fibers. The architecture consists of a two-way imaging geometry involving only one single mode fiber array. Input and output fibers belong to the same fiber array. Programmable and fixed diffractive optical elements are used for beam steering and wavefront correction. We show that the network ensures favorable conditions for launching and allows for a high interconnection volume with minimal insertion losses at 2.5 Gb/s. The architecture is also adapted to the use of binary electrically addressed spatial light modulators.     

Dynamic optical interconnection in free-space switching system

A dynamic optical interconnection system is experimented by a holographic crossbar. The pixelated multi-phase grating array displayed on spatial light modulator generated a beam array onto an arbitrary position with high efficiency in the output plane. The system operates at high speed as a free-space optical switch.     

光学全混洗网络互连函数的矩阵描述及其应用

采用自由空间光学互连技术实现的全混洗网络是数字光计算系统的基本互连网络,本文针对全混洗互连函数现有描述方法的不足,引入了描述全混洗互连函数的互连矩阵,并给出了全混洗网络互连矩阵的具体形式,为模拟或验证全混洗网络实验结果提供了理论依据。     

高分辨率快速数字化光声CT乳腺肿瘤成像

提出了一种基于聚焦线性阵列探测器的快速光声计算机断层成像技术（光声CT）.在光声二维图像重建中,根据阵列探测器机械扫描和电子扫描相结合的组合扫描模式,提出了改进的有限场滤波反投影重建算法.一方面该算法适合多元探测器旋转扫描模式,另一方面探测器的指向性函数作为反投影的权重因子提高了系统的横向分辨率.同时,该成像系统还利用柱面声透镜实现Z轴方向上的聚焦扫描以实现三维层析成像.实验中,这套成像系统空间分辨率达到0.2mm,Z轴方向分辨率为1.5mm,扫描一幅二维图像仅需150s,得到 关键词： 光声CT 有限场滤波反投影算法 声透镜聚焦 乳腺肿瘤检测     

A row–column addressed micromachined ultrasonic transducer array for surface scanning applications

Row–column addressed arrays for ultrasonic non-destructive testing (NDT) applications are analyzed and demonstrated in this paper. Simulation and experimental results of a row–column addressed 32 by 32 capacitive micromachined ultrasonic transducer (CMUT) array are presented. The CMUT array, which was designed for medical imaging applications, has a center frequency of 5.3 MHz. The CMUT array was used to perform C-scans on test objects with holes that have diameters of 1.0 mm and 0.5 mm. The array transducer has an aperture size of 4.8 mm by 4.8 mm, and it was used to scan an area of 4.0 mm by 4.0 mm. Compared to an N by N fully addressed 2-D array, a row–column addressed array of the same number of elements requires fewer (N instead of N²) pairs of interconnection and supporting electronic components such as pulsers and amplifiers. Even though the resulting field of view is limit by the aperture size, row–column addressed arrays and the row–column addressing scheme can be an alternative option of 2-D arrays for NDT applications.     

基于FPGA的DBF多波束中频接收系统的设计与实现

数字波束形成(DBF)阵列能够充分利用阵列天线所获取的空间信息,通过信号处理技术使波束获得超分辨率和低旁瓣的性能,它由天线阵元、射频下变频模块、AD采样、中频接收系统及上位机控制器组成。对中频接收系统进行数字波束形成的具体方案进行讨论,对多路接收和AD量化一致性造成的各通道间失配提出了幅相校正的解决方案,详细分析了研制中的关键技术。实验结果表明所设计的DBF多波束中频接收系统可有效实现通道间失配的校正,并实现精确的波束赋形功能。     

Integrated Optical Parallel Logic Processor Based on Birefringent Array Illuminator

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