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.     

使用光学自反关联存储技术的符号替换运算

介绍了使用光学自反关联存储技术进行符号替换运算的数学模型、数字模拟结果以及使用可编程ＬＣＴＶ液晶空间光调制器组成光电混合系统的实现符号替换的方法。这种符号替换运算具有很强的容错能力。     

声表面波扩频多符号检测器研究

报道了一种用于差分双相相移键控/双相相移键控调制信号的声表面波扩频多符号检测器;基于声表面波,实现了直接序列扩频信号匹配滤波和多符号延迟差分解调的融合;研制了13位巴克码的4符号DBPSK/BPSK扩频多符号检测器,并对该检测器进行了实验测试和性能分析.     

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.     

累积放电模型及其符号动力学研究

基于累积释放模型提出了一种累积放电模型.相比于累积释放模型, 累积放电模型无须变化的阈值调制, 即可出现多种状态, 例如混沌态、锁频等. 利用符号动力学对其进行研究, 发现在一定的参数条件下, 模型的输出符号序列可以被用于监测模型参数的变化, 而且与神经系统的测量相似, 都具有很高的分辨率. 计算机仿真和电路实验得到的结果也验证了上述说法. 电路实验结果显示模型的输出符号序列对输入频率的分辨率最高可以达到0.05 Hz, 对电流幅值的分辨率可达到1 μA, 并且都具有很大的动态范围. 关键词： 符号动力学 混沌 累积释放模型 非线性电路     

In掺杂ZnTe发光性能的第一性原理计算

利用基于密度泛函理论的第一性原理对In掺入ZnTe半导体后引入的各种缺陷进行了结构优化、 能带和态密度分析及转换能级的计算. 计算结果表明: 掺杂后体系中主要存在两种缺陷, 一种是In原子替换了Zn原子的置换型缺陷; 另一种是由In替换Zn后再与临近的Zn空位形成的复合缺陷. 二者分别在导带底下方0.26 eV和价带顶上方0.33 eV的位置形成各自的转换能级. 电子在这两个转换能级之间跃迁辐射出的能量大小与实验测量到的能量大小相符, 解释了原本发绿光的ZnTe在掺入In后发出近红外光的根本原因. 关键词： ZnTe 半导体掺杂 近红外光 第一性原理     

利用柱透镜调控涡旋光束的拓扑结构

提出了一种利用柱透镜调控涡旋光束拓扑结构的方法.利用计算全息法制作的叉形光栅掩模板,实验获得了具有不同拓扑荷的涡旋光束,分析了涡旋光束通过柱透镜变换后的强度和相位分布.结果表明,涡旋光束经柱透镜变换后,其拓扑荷符号将发生改变,并且高阶涡旋光束退化为多个分离的一阶涡旋光束.利用高阶激光模式的线性叠加特性以及古依相移对实验结果进行了理论解释,并通过数值模拟对实验结果进行了验证.     

一种实现MSD加法的光学方法

三值光学计算机系统结合光强与光的偏振方向表示三值信息,其核心器件——三值逻辑光学处理器是按照降值设计理论完成的,该处理器能完成所有19683种二元三值逻辑运算.本文旨在提出一种实现加法运算的新方法——用三值逻辑光学处理器实现加法.为了解决加法的串行进位延时问题,使用改良符号数表示进行数据编码,从而实现全并行无进位加法.用三值光学计算机与改良符号数表示相结合的方法实现加法既能够充分发挥三值光学计算机位数巨大的优势以及三值逻辑光学处理器能完成所有二元三值逻辑运算的特性,同时又发挥了改良符号数加法的无进位特点.经实验证明该方法具有可行性和正确性,是实现光学加法器的一种新思路.     

利用改进的符号数算法和光学符号代换实现矩阵计算

本文提出了一种利用改进的符号数算法和多窗口解码光学符号代换法则实现多值矩阵计算的光学方法。并给出两个多比特改进的符号数矩阵外积计算的实验结果。这一方法具有精度高、速度快等特点。     

一种实现MSD加法的光学方法

三值光学计算机系统结合光强与光的偏振方向表示三值信息,其核心器件——三值逻辑光学处理器是按照降值设计理论完成的,该处理器能完成所有19683种二元三值逻辑运算.本文旨在提出一种实现加法运算的新方法——用三值逻辑光学处理器实现加法.为了解决加法的串行进位延时问题,使用改良符号数表示进行数据编码,从而实现全并行无进位加法.用三值光学计算机与改良符号数表示相结合的方法实现加法既能够充分发挥三值光学计算机位数巨大的优势以及三值逻辑光学处理器能完成所有二元三值逻辑运算的特性,同时又发挥了改良符号数加法的无进位特点.经实验证明该方法具有可行性和正确性,是实现光学加法器的一种新思路.     

基于非线性材料二次谐波与混频特性非逻辑门运算的全光实现(英文)

Optics has already been proved as a successful candidate for conducting parallel logic, arithmetic and algebraic operations. Several all-optical data processors were proposed since last few decades. To implement these systems, different data encoding decoding techniques such as polarization encoding, tristate, quartenary state, multivalued state, symbolic substitution technique etc. have already been proposed. All these are done to use optics in a suitable platform. We propose here a new concept of encoding data by adopting frequencies variation technique for conducting a inversion operation successfully.     

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.     

基于符号替换算法的光电混合型计算机的设计

在分析符号替换算法特点的基础上，提出了基于此算法的光电混合型计算机ＯＥＨＣＢＳＳ的体系结构及其算法。性能分析表明ＯＥＨＣＢＳＳ可实现性强、性能优，特别是其光符号替换处理器具有通用性强、速度快等特点。     

A method of optical implementation of frequency encoded different logic operations using second harmonic and difference frequency generation techniques in non-linear material

Optics has already been proved its successful roles for conduction of parallel logic, arithmetic and algebraic operations. Since last few decades many types of optical data processors were proposed. To implement these processors different data encoding/decoding techniques have been reported. In this context polarization encoding technique, tristate, quartenary logic, multivalued logic, symbolic substitution techniques etc. may be mentioned. Very recently, frequency encoding/decoding technique have also been well established. The potential advantage of frequency dependent encoding/decoding is that, as the frequency being the fundamental character of a signal; it will remain unaltered in reflection, refraction, absorption etc. during transmission of the signal. In this communication the authors propose a scheme for implementing different logic operations adopting frequency based encoding technique. For this purpose the second harmonic generation and difference frequency generation techniques are used by exploiting the non-linear response character of some materials.     

Method of implementing frequency-encoded NOT,OR and NOR logic operations using lithium niobate waveguide and reflecting semiconductor optical amplifiers

Optics has already proved its strong potentiality for the conduction of parallel logic, arithmetic and algebraic operations. In the last few decades several all-optical data processors were proposed. To implement these processors different data encoding/decoding techniques have been reported. In this context, polarization encoding technique, intensitybased encoding technique, tristate and quaternary logic operation, multivalued logic operations, symbolic substitution techniques etc. may be mentioned. Very recently, frequency encoding/decoding technique has drawn interest from the scientific community. Frequency is the fundamental character of any signal; and it remains unaltered in reflection, refraction, absorption etc. during the propagation and transmission of the signal. This is the most important advantage of frequency encoding technique over the conventional encoding techniques. In this communication the authors propose a new scheme for implementing NOT, OR and NOR logic operations. For this purpose co-propagating beams having different frequencies in C-band (1535–1560 nm) have been used for generating cascaded sum and difference frequency, exploiting the nonlinear response character of periodically poled LiNbO₃ waveguide. The cross-gain modulation property of the semiconductor optical amplifier (SOA) and the wavelength conversion property of the reflecting semiconductor optical amplifiers (RSOA) are exploited here to implement the desired optical logic and arithmetic operations.     

Symbolic substitution based flagged arithmetic unit design using polarization-encoded optical shadow-casting system

An extremely efficient modified-signed digit arithmetic unit based on symbolic substitution scheme is designed using the polarization-encoded optical shadow-casting system. Alternate design characteristics for both addition and subtraction are also presented.