Cellular processing for edge detection in an optical shadow casted architecture

The principles of two-dimensional cellular processing are utilized to obtain the edges of a binary image in an optical shadow casted architecture. The processing steps, based on image logic algebra are introduced where operation kernels are set by the on/off states of four light sources. The input binary image is shifted, superimposed, then logically operated and finally decoded to obtain the edges. The whole process is controlled by a microcomputer. Experimentally simulated results are presented.     

Real-Time Reconfigurable Interconnections for Parallel Optical Processing

In this letter we describe the advantages of a dynamic optical interconnection system for parallel information processing applications. The system is based on a liquid crystal television which acts as a binary phase-only spatial light modulator. We describe example algorithms where reconfigurable interconnects would be useful and present results of several interconnection topologies which have been implemented.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.     

Modified signed-digit addition by using binary logic operations and its optoelectronic implementation

In this work, a three-step modified signed-digit (MSD) addition by using binary logic operations is proposed. Each input digit is encoded with two binary bits. Through binary logic operations, all of the weight and transfer digits and the final sum digits represented with the same encoding scheme will be generated. The operations can be performed at each digit position in parallel. In our suggested optical arithmetic and logic unit (ALU), a single electron trapping (ET) device is employed to serve as the binary logic device. This technique based on ET logic possesses the advantage of high signal-to-noise ratio (SNR). The optoelectronic system can be constructed in a simple, compact and general-purpose form.     

When optical microscopy meets all-optical analog computing: A brief review

As a revolutionary observation tool in life science, biomedical, and material science, optical microscopy allows imaging of samples with high spatial resolution and a wide field of view. However, conventional microscopy methods are limited to single imaging and cannot accomplish real-time image processing. The edge detection, image enhancement and phase visualization schemes have attracted great interest with the rapid development of optical analog computing. The two main physical mechanisms that enable optical analog computing originate from two geometric phases: the spin-redirection Rytov-Vlasimirskii-Berry (RVB) phase and the Pancharatnam-Berry (PB) phase. Here, we review the basic principles and recent research progress of the RVB phase and PB phase based optical differentiators. Then we focus on the innovative and emerging applications of optical analog computing in microscopic imaging. Optical analog computing is accelerating the transformation of information processing from classical imaging to quantum techniques. Its intersection with optical microscopy opens opportunities for the development of versatile and compact optical microscopy systems.     

Performance Comparison and Evaluation of Options for Arranging Data in Digital Optical Parallel Computing

Performances of options for arranging data in the input images of digital optical computing are analyzed and evaluated on the basis of the characteristic functions that the authors formularized. The methods for arranging the data are classified into two options: the spatially expanded bit-pattern arrangement (SEPA) and the bit-slice arrangement (BSA). To analyze and evaluate the performance, the options are applied to the parallel operations based on the optical array logic that is a paradigm of digital parallel computing. Processing steps, storage capacity, and scale of the operation kernel required for performing various parallel operations are analyzed as the characteristic functions. The performances of the SEPA and the BSA are evaluated by comparing these functions. The features of each option are clarified and a guideline for choosing the optimal option is proposed to efficiently perform digital parallel optical operations.     

用投影法实现符号代换

本文提出了一种实现符号代换的方法.将无透镜投影系统与一个顺序逻辑门阵列和记录装置结合,构成了一个实现符号代换的装置.采用发光二极管(LED)做光源,同时做运算的控制元件,使符号代换的过程实现完全的光电操作.给出了实验的原理、过程及结果.     

Unified negabinary symbolic arithmetic for addition and subtraction with polarization-encoded optical shadow casting

Conventional algorithms process addition and subtraction in different ways. In this paper, by introducing bipolar carries, a unified negabinary symbolic arithmetic for the two operations can be derived, using only the same six substitution rules. Based on the polarization-encoded optical shadow-casting technique, the encoding and decoding patterns for half-addition, half-subtraction and unified arithmetic are designed, with the fixed LED pattern and separate and simultaneous generation of the multi-outputs. The architecture is simple, programmable, cost-efficient, and the addition and subtraction of multiple pairs of bipolar numbers can be handled in parallel in the same manner.     

Photonic Implementation of Quantum Computation Algorithm Based on Spatial Coding

Several implementation methods of quantum computation algorithm by conventional computer have been explored for large-scale emulation. Due to the lack of quantum effects, these methods generally require exponential growth of the size of the hardware with increase of the number of qubits. In this paper, the spatial coding, which is an effective digital optical computing technique, is studied as an efficient implementation method of quantum computation algorithms. In the proposed scheme, quantum information is represented by the intensity and the phase of elemental cells. We confirmed correct operation of the quantum teleportation algorithm by computer simulation. We also demonstrated a photonic implementation of some of the quantum gates experimentally.     

Optical array logic network computing: Design of a prototype system

We present the architecture of novel optoelectronic parallel computing called optical array logic network computing (OAL-NC). In the OAL-NC, electronic processing elements execute local operations, whereas an optical network processor is dedicated to global operations as well as data transfer. As a prototype of the OAL-NC, a 16x16 pixel system is designed at a logical level. Issues associated with the design task are discussed.     

All optical frequency encoding method for converting a decimal number to its equivalent binary number using tree architecture

In any kind of computing and data processing system the use of binary numbers are found very much suitable and reliable. On the other hand several natural representations have been realized using decimal numbers. So conversion of a decimal number to its binary equivalent and vise-versa are of great importance in the field of computation technology. There lie already a number of established methods regarding such conversion processes. Again optical tree architecture is one of the most promising systems for realizing the optical conversion of any decimal number to its equivalent binary. Here in this communication the authors propose a new method for optical conversion of a decimal number to its binary equivalent using tree architecture based system and frequency encoding principle. In frequency encoding system, frequency of light is used for encoding of decimal digits or binary bits instead of intensity variation. For example 0 and 1 bits of binary number are coded by two different frequencies of light signal, instead of representing the presence of light as 1 and absence by 0. The proposed conversion process has multifaceted advantages in communication, as well as in data processing. To implement the above conversion some characteristic features of semiconductor optical amplifier (SOA) have been used massively. The wavelength conversion property, cross gain modulation and some nonlinear properties of SOA are exploited to get the frequency encoded response. The proposed system carries all the basic advantages of optical processing as well as those of frequency encoding also.     

非制冷长波红外热像仪折衍混合双视场光学系统设计

根据衍射光学元件具有大的负向色散特性,将衍射光学元件应用于红外双视场光学系统中,根据傅里叶光学分析衍射光学元件(DOE)的消色差,列表对比折射透镜与衍射光学透镜的特性,并给出变倍比为4∶1可用作非制冷红外热像仪的光学系统的具体设计实例.系统采用切入式变焦方式,在短焦时切入2片透镜实现宽视场,通过引入二元面和非球面提高了成像质量.设计结果表明:在空间频率11 lp/mm处,短焦距40 mm时,各个视场的MTF值均大于0.6;长焦距160 mm时,各个视场的MTF值均大于0.7,宽视场和窄视场都具有较好的成像质量.     

光学元件表面缺陷的显微散射暗场成像及数字化评价系统

根据国际ISO10110-7的表面缺陷标准及惯性约束聚变(ICF)工程标准,提出了一种新颖的光学元件表面缺陷的光学显微散射成像及数字化评价系统,多束光纤冷光源呈环状分布并以一定角度斜入射到数毫米视场的被检表面,形成适合数字图像二值化处理的暗背景上的亮疵病图像。对X,Y两方向进行子孔径图像扫描成像,利用模板匹配原理对获得的子孔径图像进行拼接得到全孔径表面疵病图像信息。基于数学形态学建立了可用于大口径表面检测扫描的图像处理的模式识别软件体系,并应用二元光学制作了标准对比板,以获得疵病正确的评价依据。最终利用该变倍光学显微镜散射成像系统得到能分辨微米量级表面疵病的图像,其单个子孔径物方视场约为3 mm,对X,Y两方向进行5×5子孔径图像扫描成像,并给出了与标准比对的定量数据结果。实验结果表明,本系统完全可以实现光学元件表面缺陷的数字化评价。     

光学并行实现模糊逻辑图像处理

提出和验证一种基于偏振－空间编码方案和多重成像技术的光学方法来实现模糊逻辑图像处理,系统中,模糊变量和它们的补被编码为空间正交分布的两个偏振状态。通过对透镜阵列状态的编程,可以实现两个模糊图像间的模糊逻辑操作。本系统中,两个输入图像被偏振编码为8个编码图像作为输入图像,系统是空不变系统,不需要取阈装置和解码过程,通过引进取阈装置,可以在一层系统中实现两个图像间更为复杂的模糊逻辑操作,并给出了实验结果。     

A hybrid optical-digital processor for image deblurring

A hybrid optical-digital image processing system is developed for deblurring out-of-focus pictures. The optical part is a dual-channel non-coherent processor which implements the Wiener filter for deblurring through appropriate pupil functions. The methods of implementing the bipolar PSF in a non-coherent processor are described, as are the methods of determining the pupil functions from the given PSFs. The digital part of the processor subtracts or demodulates the outputs from the dual-channel optical processor to give the final deblurred picture. The pupil functions are experimentally realized and the deblurred outputs are presented.     

自由曲面光学系统设计及其应用

介绍了自由曲面光学系统研究背景,自由曲面描述方法,光学设计中的逐步逼近优化和像质自动平衡优化两种算法。并以实际应用中的头盔光学系统设计及大视场、高分辨率头盔显示器的设计为例对这些方面进行分析,讲解了自由曲面光学系统设计及其应用。     

High efficiency redundant binary number representations for parallel arithmetic on optical computers

A family of redundant binary number representations, obtained by generalization of the RB (redundant binary) number representation, is introduced. All these number representations are suitable for optical computing and have properties similar to the RB representation. In particular, the p-RB (packed redundant binary) number representation introduced in this work has efficiency greater than both RB and MSD (modified signed digit) representations. With p-RB numbers the algebraic sum is always permitted in constant time for any efficiency value. p-RB representations also fit in a natural way the 2's complement binary number system. Symbolic substitution truth tables for the algebraic sum and several examples of computation are also given.     

基于光学沃尔什变换特征提取的图像匹配

采用光电结合的方法实现了沃尔什 （Walsh）分量变换,提出出反映图像主要特征的分量,用于大容量图像库的内容匹配查找,基于以非相干光相关器为核心的光电混合图像处理系统,实现了基于光学沃尔什变换特征提取的图像匹配算法。     

One-operation image algebra for optical processing

A binary image algebra with one operation of a logic operation followed by a dilation and its modification with three additional operations for threshold processing of grey level images are developed in this paper. All the binary image processing functions and various grey level image processing functions related to morphological operations can be represented by the algebraic structure. The algebra is particularly suitable for parallel processing by optics in a cellular logic image processor architecture.     

二元光学透镜在资源卫星中的应用

使用一种基于二元光学透镜的分光成像及消色差原理的新方法来设计资源卫星的中继光学系统。通过分析二元光学透镜的分光成像原理、消色差原理、衍射效率与阶数和工作波长及设计波长的比之间的关系,又考虑到单独设计制造二元光学透镜的难度,采用折衍混合成像光学系统来拟定资源卫星中继光学系统的设计方案,给出用ZEMAX软件设计的具体结果。设计实例及分析结果表明,包含二元光学透镜的折衍混合成像系统可以很好的实现光谱波段分离,用于资源卫星的光学系统具有一定的适用性。     

放大率恒定的二元光学超光谱成像仪光学系统设计

二元光学元件具有多种应用。用作透镜，在原理上色差非常大，若不在设计上做出补偿，则会限制其在宽波段上的使用。从理论上简单阐述了利用具有独特色散特性的二元光学元件的新型超光谱成像仪的基本原理和应用前景。在此超光谱成像仪中，二元光学透镜焦距随波长的变化改变了系统的F数，因此改变了系统的放大率，既系统放大率是波长的函数，这将引起光谱图像的像元配准误差，得到并不精确的相对光谱信号强度，从而限制了光谱图像重建算法的精度，为了补偿这一缺点，通过光学二组元法设计的变焦系统成功地解决了这一问题，并给出了理论设计公式。