一种实现二进制加法符号替换规律的光逻辑系统

为了实现二进制加法符号替换规律,本文提出了一种简单的光逻辑系统,它仅包括一片二维列阵光学双稳器件.本实验采用同时具有NXOR和OR逻辑功能的透反射型ZnS光学双稳干涉滤光片作光逻辑器件.该光学逻辑系统完成了二进制加法四个符号替换规律的并行替换.光学系统采用固定的自由空间互连方法,具有光学硬件少,光功率损耗低,结构简单、实用的优点.     

三个二进制输入双通道输出的光学并行逻辑运算

本文利用一种光学投影系统实现了具有三个二进制输入、双通道输出的光学并行逻辑运算。利用我们的方法可以实现三个二进制输入的所有256种布尔逻辑运算,由于是双通道输出,还可以方便地得到全加器输出结果。最后,本文还提出了一种实现输入图形实时编码的光学系统。     

绝对式光学编码器串行编码方法的研究

针对传统绝对式光学编码器各编码码道沿径向分布、结构复杂的缺点,提出了一种绝对式光学编码器的串行编码方法。在码盘上仅刻划一圈存储多位二值信息的编码码道,沿码盘圆周方向按一定位置布置的光敏元件并行读取的二进制数具有唯一性,对此二进制数查表译码,就可以实现绝对位置测量。与传统绝对式光学编码器相比,码盘直径小、光学图案简单,有利于绝对式编码器实现小型化和提高精度。     

线照明并行谱域光学相干层析成像系统与缺陷检测应用研究

针对玻璃缺陷在线无损检测的迫切需求,本文报道了一种基于线照明并行谱域光学相干层析成像系统的大视场检测系统.该系统采用快速面阵CMOS相机,单次拍摄即可获取完整的横截面(B-scan)图像.基于线照明面阵探测器的并行谱域光学相干层析成像系统,可以同时获取沿线照明方向各位置处的深度分辨信息,避免了横向扫描机构的应用.研制系统的轴向分辨率为17.9μm,并行方向上的横向分辨率55.7μm,扫描方向上的横向分辨率为24.8μm,轴向扫描速率为128 000 A-scan/s,横向视场为32 mm,空气中成像深度大于6 mm,成像灵敏度达到62 dB以上.利用研制的线照明并行谱域光学相干层析成像系统,开展了不同类型玻璃表面及其内部缺陷的检测应用研究.     

基于光学相控阵的目标指示系统

为实现对运动目标实时指示激光束的非机械电控制,建立了基于光学相控阵的目标指示系统.首先,根据光学相控阵原理和空间光调制特性,对预设指示图添加共轭对称项,利用快速傅里叶变换计算全息法生成的全息图进行制表.其次,在图像传感器采集视频下,运用基于核函数密度估计的改进Mean-shift目标跟踪算法,获取多目标位置信息,查表并载入全息信息,完成全息图的实时更新.最后,利用空间光滤波特性,设计光电再现环节,消去冗余项并完成全息再现过程.实验发现:对8bit灰度全息图,系统每秒的指示速度均在60帧以上,各部件效能达到最大化.满足了目标指示系统稳定性、实时性、准确性等要求,理论算法和实验结果也验证了该系统的有效性.     

二进制信号的混沌压缩测量与重构

二进制信号的压缩感知问题对应超奈奎斯特信号系统中未编码的二进制符号的检测问题, 具有重要的研究意义. 已有的二进制信号压缩测量采用高斯随机矩阵, 信号重构采用经典的l₁最小化方法. 本文利用混沌映射构造基于Cat序列的循环测量矩阵, 并提出一种针对二进制信号的全新的重构算法——平滑函数逼近法. 文章构造的混沌循环测量矩阵兼具确定性和随机性的优点, 能够抵御低信令效率和低信噪比的影响, 取得更好的压缩测量效果. 文章提出的平滑函数逼近法利用非凸函数代替原问题不连续的目标函数, 将组合优化问题转化为具有等式约束的优化问题进行求解. 利用稀疏贝叶斯学习算法进一步修正误差, 得到更准确的重构信号. 在信道含有加性高斯白噪声的条件下对二进制信号进行了压缩测量与重构的数值仿真, 仿真结果表明:基于Cat 序列的循环测量矩阵的压缩测量效果明显优于传统的高斯随机矩阵; 平滑函数逼近法对二进制信号的重构性能明显优于经典的l₁最小化方法.     

激光局域网络的混沌控制及并行队列同步

本文提出并研究了"单队列-双参数"光电延时反馈控制条件下的激光局域网络的混沌控制及串联的动力学行为的并行队列"交叉驱动-反馈"网络同步实现,建立了该光学局域网络的数学物理控制模型.通过含时延超越方程理论的分析,预言了该光学局域网络是可以实现混沌控制的,且网络两路结点队列是可以实现实时引导控制到多个类周期状态上的,并通过并行队列同步方程理论证明并行串联队列同步是可以获得的.结果发现在可控的激光局域网络两个并行串联队列光路上,分别实现了网络队列结点的混沌控制并能够实现多个类周期的网络结点的并行串联队列同步,实现了络网结点激光器的2周期、3周期、4周期等状态的并行队列同步,以及其他多个类周期的队列并行同步和动态同步.还发现了两个类周期并行队列网络同步控制区域.本文还给出了激光局域网络"并行多点混沌载波同步发射及其在光学超宽带通信中应用"的一个案例并成功实现.这是一种新型的激光混沌局域网络控制系统,具有光局域网络光传送与光联接核心控制技术要素,具有复杂动力学系统与网络的多变量、多空间维度及并行两路不同队列混沌控制技术特点,还具有光网络超宽带通信功能等.其研究结果对局域网络、光网络的控制与同步、激光技术以及混沌的研究具有重要的参考价值.     

基于光学扫描全息密码术的多图像并行加密

对光学扫描全息术中的双光瞳做出改进,提出对多图像并行加密和任意层图像再现的新方法.将其中一个光瞳设置成环形光瞳,另一个光瞳处插入随机相位板,干涉形成环形随机相位板,实现对多层图像的快速扫描和并行加密,扫描信号通过计算机合成为加密全息图,在数字全息再现的过程中进行解密,实现对任意层图像的精准重建.该方法快捷高效、安全可靠,抗噪声能力强.利用相关系数评估了该方法的加密效果,并通过仿真实验验证了该方法的有效性和安全性.     

负二进制编码的光学阵列化复数运算

建立一套新颖的光学负二进制并行算法体系，包括加权－移位加法、列阵乘法等。一切运算无符号位、无进位、无再编码。利用两层阵列可实现高精度的复数运算，三层阵列可实现复数矩阵－矢量运算。该算法体系非常适合于光学执行。相应地，文中给出了两层列阵复数相乘光学系统及实验结果。原理上，该算法是可级联的。     

微粗糙光学基片表面与上方冗余粒子的差值场散射特性研究

基于小波距量法(MOM)研究了微粗糙光学基片表面与上方冗余粒子的差值光散射特性。从基本电场积分方程出发,推导出冗余粒子目标与光学基片微粗糙面的积分方程,得到阻抗矩阵,进而推导出散射耦合场及差值场,给出复合散射模型双站散射截面的计算公式,数值计算并分析了不同入射角度,不同材质的单个及双个冗余缺陷粒子与微粗糙光学基片表面的双站散射截面及差值双站散射截面的散射角分布,给出冗余粒子及微粗糙面的散射贡献及差值场散射角分布。     

One-step optical trinary signed-digit arithmetic using redundant bit representations

A simple one-step fully parallel trinary signed-digit arithmetic is proposed for parallel optical computing. This technique performs multidigit carry-free addition and borrow-free subtraction in constant time. The trinary signed-digit arithmetic operations are based on redundant bit representation of the digits. Optical implementation of the proposed arithmetic can be carried out using correlation or matrix multiplication based schemes. An efficient matrix multiplication based optical implementation that employs a fixed number of minterms for any operand length is developed. It is shown that only 30 minterms (less than recently reported techniques) are enough for implementing the one-step trinary addition and subtraction.     

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.     

All-optical conversion scheme from binary to its MTN form with the help of nonlinear material based tree-net architecture

In the field of optical computing and parallel information processing, several number systems have been used for different arithmetic and algebraic operations. Therefore an efficient conversion scheme from one number system to another is very important. Modified trinary number (MTN) has already taken a significant role towards carry and borrow free arithmetic operations. In this communication, we propose a tree-net architecture based all optical conversion scheme from binary number to its MTN form. Optical switch using nonlinear material (NLM) plays an important role.     

Circuit designs of ultra-fast all-optical modified signed-digit adders using semiconductor optical amplifier and Mach-Zehnder interferometer

The need for increasingly high-speed digital optical systems and optical processors demands ultra-fast all-optical logic and arithmetic units. In this paper, we combine the attractive and powerful parallelism property of the modified signed-digit (MSD) number representation with the ultra-fast all-optical switching property of the semiconductor optical amplifier and Mach-Zehnder interferometer (SOA-MZI) to design and implement all-optical MSD adder/subtracter circuits. Non-minimized and minimized techniques are presented to design and realize efficient circuits to perform arithmetic operations. Several all-optical circuits’ designs are proposed with the objective to minimize the number of the SOA-MZI switches, the time delay units in the adders, and other optical elements. To use the switching property of the SOA-MZI structure, two bits per digit binary encoding for each of the trinary MSD digits are used. The proposed optical circuits will be very helpful in developing hardware modules for optical digital computing processors.     

Terahertz optical asymmetric demultiplexer based tree-net architecture for all-optical conversion scheme from binary to its other 2n radix based form

To exploit the parallelism of optics in data processing,a suitable number system and an efficient encoding/decoding scheme for handling the data are very essential.In the field of optical computing and parallel information processing,several number systems like binary,quaternary,octal,hexadecimal,etc.have been used for different arithmetic and algebraic operations.Here,we have proposed an all-optical conversion scheme from its binary to its other 2n radix based form with the help of terahertz optical asymmetric demultiplexer (TOAD) based tree-net architecture.     

Optoelectronic symbolic substitution based canonical modified signed-digit arithmetic

A single-step optoelectronics symbolic substitution scheme to handle parallel modified signed-digit (MSD) arithmetic operations is proposed. Conversion algorithms from MSD numbers into a canonical MSD representation are provided. The canonical MSD numbers have the property that no two consecutive digits are non-zero. The addition operation of two CMSD numbers is performed in one step. It will be shown that through the use of CMSD representation, the number of symbolic substitution rules in an optical content-addressable memory (CAM) based system is significantly reduced. The number of symbolic substitution rules can be further reduced to an optimum value through a proposed shared content-addressable memory optical set-up. Further, the proposed optical scheme doubles the storage efficiency of the shared content-addressable memory.     

An all optical approach for developing a system involving Kerr material based switches for cryptographic encoding of binary data depending on the input parity

Optics is a highly potential candidate in super fast data computation and communication because of its strong inherent parallelism. Several all optical logic, arithmetic and data processing systems have been proposed in the last few decades. Many all optical digital encoders and decoders are also reported. In this paper we propose a new and alternative concept of using optics for encrypting a binary number to a suitable binary code to achieve a secured optical communication. This binary number can bear the supporting alphabets and numerals in communication of data. In this process an encrypted data is checked by necessary parity bit to ensure a secure communication. The result is verified using proper simulation.     

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.     

A new method of binary addition scheme with massive use of non-linear material based system

The limitations in electronics in arithmetic, algebraic & logic processing are well known. Very high speed performance (above GHz) are not expected at all in conventional electronic mechanism. To achieve high speed performance we may think on the introduction of optics instead of electronics for information, processing and computing. Non-linear optical material is a successful candidate in this regard to play a major role in the optically controlled switching systems and therefore in all-optical parallel computation these materials can show a very good potential aspect. In this paper, we have proposed a new method of an optical half adder as well as full adder circuit for binary addition using non-linear and linear optical materials.     

Investigation of Deuterium Substitution Effects in a Polymer Membrane Using IR Fourier Spectrometry

Since last few decades optics has already proved its strong potentiality for conducting parallel logic, arithmetic and algebraic operations due to its super-fast speed in communication and computation. So many different logical and sequential operations using all optical frequency encoding technique have been proposed by several authors. Here, we have keened out all optical dibit representation technique, which has the advantages of high speed operation as well as reducing the bit error problem. Exploiting this phenomenon, we have proposed all optical frequency encoded dibit based XOR and XNOR logic gates using the optical switches like add/drop multiplexer (ADM) and reflected semiconductor optical amplifier (RSOA). Also the operations of these gates have been verified through proper simulation using MATLAB (R2008a).