光致异构全光逻辑门理论与实验研究

基于双光抽运探测模型，利用偶氮苯聚合物光致异构和光致双折射效应，建立了全光逻辑门的理论分析模型，提出了一种新颖的全光逻辑门设计方案.该方案基于输入抽运光和信号光的强度或偏振态，设计了“与”门、“或”门、“异或”门和“异或非”门等基本功能的全光逻辑门.以掺杂分散红1(DR1)的聚甲基丙烯酸甲酯(PMMA)薄膜为样品进行实验，得到了比较好的逻辑门运算实验结果，与理论分析相符合.     

细菌视紫红质在全光逻辑器件中的研究与应用

介绍了细菌视紫红质在逻辑器件中的研究与应用,总结了利用细菌视紫红质研究逻辑器件的方法,明确进一步研究逻辑器件的发展方向是智能化器件的开发.     

基于同一结构实现全光逻辑“与门”和“或非门”的研究

提出了一种基于同一结构实现全光逻辑“与门”和“或非门”的新型方案，其理论基础是级联单端半导体光放大器(SOA)的交叉增益调制效应.利用单端SOA的动态理论模型成功地模拟了输入信号光为20Gb/s固定格式非归零信号时，该方案分别得到逻辑“与”和逻辑“或非”两种不同的输出结果.最后进行了实验验证，模拟结果和实验结果基本相符. 关键词： 半导体光放大器 交叉增益调制 全光逻辑     

基于高非线性光纤中非线性偏振旋转效应的全光逻辑门研究

提出了一种新型的基于高非线性光纤(HNLF)中非线性 偏振旋转(NPR)效应的全光逻辑门实现方案. 将两路非归零码数据信号A和B以及一路直流光同时注入HNLF, 光功率变化导致的非线性双折射在两个偏振分量上引入非线性相对相移, 从而导致光信号的偏振态旋转. 在HNLF输出端, 通过波分解复用器和偏振分束器同时滤出数据信号和直流光的正交偏振态, 从而同时实现多种基础组合逻辑, 并可以在同一段HNLF中实现较为复杂的半加器、半减器逻辑功能. 理论分析了信号光在HNLF中的偏振态演化, 以及利用HNLF中的NPR效应同时实现多种全光逻辑门的原理. 并在实验中得到了10 Gbit/s全光信号"与”、"非”、"或”、"同或”、"异或”、"A· B”、"A·B”、半加器、半减器等逻辑功能, 验证了方案的可行性.     

新型全光逻辑与门的理论和实验研究

提出一种基于级联单端半导体光放大器（SOA）中交叉增益调制效应的新型全光逻辑与门， 建立了该方案的理论模型，数值模拟和实验实现了10Gb/s的全光逻辑与运算功能，分析了逻辑与运算结果与输入信号功率和消光比之间的关系，理论分析结果与实验结果相符合. 关键词： 半导体光放大器 交叉增益调制 全光逻辑与门     

All-optical integrated logic gates based on intensity-dependent transverse modal coupling

We present a study of the spatial propagation of light in a third order planar step-index waveguide with a transverse parabolic width film. By using the Lagrangian formalism, the width and phase evolution of a Gaussian beam has been completely described showing both the refractive contributions of the lens-like waveguiding geometry and self-focusing nonlinearity. As a result of this study, we have proposed the design of a new kind of integrated all-optical devices which, by means of the spatial beam power modulation and its influence on the transverse modal coupling can operate as phase-insensitive AND, OR and XOR logic gates.     

基于半导体材料微纳波导全光逻辑门的研究进展

全光逻辑门是全光计算以及全光信号处理系统中关键的光子器件.随着互补金属氧化物半导体(COMS)工艺的发展,基于半导体材料微纳波导全光逻辑门已经成为集成光学领域中的重要方向;尤其是硅基光子集成器件在近些年成为了国际研究热点.文章主要对基于绝缘体上的硅(SOD)和Ⅲ-Ⅴ族化合物材料不同波导结构(马赫-曾德尔干涉仪(Mach-Zehnder interferometer)微环谐振腔和条形波导结构)的全光逻辑门的研究进展进行了介绍,并且在器件的工作速率和功耗方面,分别对上述基于SOI和Ⅲ-Ⅴ族化合物材料三种不同波导结构的全光逻辑门进行了分析和比较.     

基于半导体光纤环形腔激光器的新型全光AND门和NOR门

提出了一种新型的基于半导体光纤环形腔激光器(SFRL)中同时发生的四波混频效应和交叉增益调制效应同时实现全光AND门和NOR门方案，并建立了这种全光逻辑门完整的宽带理论模型.通过数值模拟的方法，研究了输入信号光峰值功率及SFRL中两个耦合器的耦合比对这种全光逻辑门输出特性的影响. 关键词： 半导体光纤环形腔激光器 全光逻辑门 四波混频 交叉增益调制     

All-optical method of developing some fundamental and functional quaternary logic gates

All optical multivalued logic processors are of paramount importance in optical computing and signal processing. In this article the author proposes a method of developing all-optical quaternary Inversion, NOT and Bitswap logic gates, which are essential parts of quaternary arithmetic and logical processors. Nonlinear switching and add/drop multiplexing (ADM) properties of semiconductor optical amplifier (SOA) are exploited here to develop the frequency encoded quaternary logic gates.     

Design of ultra compact all-optical XOR and AND logic gates with low power consumption

We propose a novel ultra-compact all-optical XOR and AND logic gates without using nonlinear optics. In order to realize these devices, we adopt photonic crystal waveguides (PCWs) based on multi-mode interference devices. Numerical results show that the operating bandwidth of the ON to OFF logic-level contrast ratio of not less than 6.79 dB is 35 nm for XOR logic gate and 9 nm for AND logic gate. Proposed logic gates have the potential to be key components for an optical packet switching system due to their small feature sizes and low power consumption.     

Stochastic resonance, reverse-resonance and stochastic multi-resonance in an underdamped quartic double-well potential with noise and delay

The stochastic resonance in an underdamped quartic double-well potential with time delayed feedback is studied numerically. The signal power amplification is employed to characterize the stochastic resonance of the system. Simulation results indicate that: (i) for moderate frequency of the periodic driving, the stochastic resonance is decreased monotonically by increasing the delay time, but at high frequency, the reverse-resonance is induced to transform into a stochastic resonance by time delay; (ii) the damping coefficient has a critical value for which the stochastic resonance is optimum; (iii) a stochastic multi-resonance emerges when the signal power amplification is a function of the driving frequency.     

基于频率调制激光驱动的囚禁离子几何相位逻辑门

为了避免激光相位的起伏对几何相位逻辑门保真度的影响, 提出一种基于囚禁离子的量子几何相位逻辑门的新方案。该机制是利用一束频率调制的行波激光场作用于两个囚禁离子上实现的。它的优点有：操作简单,仅需一步就能实现。不灵敏于激光场的相位也不需要对囚禁离子进行个别寻址。     

基于偏振叠加和干涉两种方法的可控光脉冲延时器

可控的光信号延时在科研和通信领域有着广泛的应用.本文提出了两种可控光脉冲延时器的方案,分别基于偏振叠加和干涉原理.通过相位调制器的调制将光脉冲约束在一个环路中,需要时再释放,以达到光脉冲延时的目的.调节环路的长度和循环的次数便可以实现延时时间的可控.这两种方案均可以应用于全光纤光路中,通过集成光学技术可以实现微小尺寸的封装.基于偏振叠加的方案还可以方便地应用于自由空间光延时. 关键词： 光延时 可控 偏振 干涉     

Effects of time delay on stochastic resonance of a periodically driven linear system with multiplicative and periodically modulated additive white noises

Stochastic resonance (SR) of a periodically driven time-delayed linear system with multiplicative white noise and periodically modulated additive white noise is investigated. In the condition of small delay time, an approximate analytical expression of output signal-to-noise ratio (SNR) is obtained. The analytical results indicate that (1) there exists a resonance peak in the curve for SNR versus time delay; (2) the time delay will suspend the SR dramatically for SNR versus other parameters of the system, such as noise intensity, correlation intensity, and signal frequency, once a certain value is reached, the SR phenomenon disappears.     

小世界神经元网络随机共振现象:混合突触和部分时滞的影响

实际神经元网络中,信息传递时电突触和化学突触同时存在,并且有些神经元间的时滞很小可以忽略.本文构建了带有不同类型突触耦合的小世界网络,研究部分时滞、混合突触及噪声对随机共振的影响.结果表明:兴奋性和抑制性突触的比例影响共振的产生;在抑制性突触为主的网络里,几乎不产生随机共振.系统最佳噪声强度和化学突触比例大致呈线性递增关系;特别是在以化学耦合为主的混合突触网络里,仅当兴奋性突触与抑制性突触比例约为4:1时,噪声才可诱导网络产生共振行为.在此比例下,引入部分时滞发现时滞可诱导网络产生随机多共振,且随网络中时滞边比例的增加,系统响应强度达到最优水平的时滞取值区间逐渐变窄;同时发现,网络中含有的化学突触越多,部分时滞诱导产生的多共振行为越强.此外,当时滞为系统固有周期的整数倍时,时滞越大共振所对应的噪声区域越广;并且网络中时滞边越多,越容易促使噪声和时滞诱导其产生明显的共振行为.     

A method of implementation of frequency encoded all optical logic gates based on non-linear total reflectional switch at the interface

A novel method of implementation of frequency encoded logic gates NOT, OR, AND, NOR, NAND, X-OR, X-NOR is discussed. The frequency sources and physical requirements for the implementation are also discussed. The non-linear material (liquid) suitable for these operations to be performed should be of large non-linear coefficient, high reverse saturation absorption, large thermo-optic coefficient and low viscosity. The input controlling beams used to induce non-linearity in the switch are either of frequency υ₁ or υ₂ and the probe beam is a mixed signal of frequencies υ₁ and υ₂. Depending on the nature of the controlling inputs the output conditions of the probe can be adjusted to get different logic gates.     

Analytical and simulative studies on optical NOR and controlled NOR logic gates with semiconductor optical amplifier

Semiconductor optical amplifier (SOA) is used for different successful frequency based switching operations. In this paper the authors describe the simulation study of the performances of SOA in various optical switches like frequency conversion, add-drop multiplexer and frequency encoded optical NOR gate, which is one the most important gates in logic family as it is known as one of the universal logic gates. Again, the controlled optical NOR logic operation with semiconductor optical amplifier is also proposed in this paper.     

All-optical NOT and XOR logic operation at 2.5 Gb／s based on semiconductor optical amplifier loop mirror

All-optical XOR and NOT logic operations based on semiconductor optical amplifier loop mirror (SLALOM) aresimultaneously demonstrated theoretically and experimentally. Based on a segmented semiconductor optical amplifier model, the all-optical logic operation process is simulated theoretically. In an experimental study, 2.5 Gb/s all-optical XOR operation was achieved in the output port of SLALOM, while all-optical NOT operation was achieved in the input port through a circulator at the same time.     

Robust stability analysis for Markovian jumping stochastic neural networks with mode-dependent time-varying interval delay and multiplicative noise

This paper is concerned with the problem of robust stability for a class of Markovian jumping stochastic neural networks (MJSNNs) subject to mode-dependent time-varying interval delay and state-multiplicative noise. Based on the Lyapunov--Krasovskii functional and a stochastic analysis approach, some new delay-dependent sufficient conditions are obtained in the linear matrix inequality (LMI) format such that delayed MJSNNs are globally asymptotically stable in the mean-square sense for all admissible uncertainties. An important feature of the results is that the stability criteria are dependent on not only the lower bound and upper bound of delay for all modes but also the covariance matrix consisting of the correlation coefficient. Numerical examples are given to illustrate the effectiveness.     

Investigation on performance of all optical buffer with large dynamical delay time based on cascaded double loop optical buffers

Optical buffers are critical for optical signal processing in future optical packet-switched networks. In this paper, a theoretical study as well as an experimental demonstration on a new optical buffer with large dynamical delay time is carried out based on cascaded double loop optical buffers (DLOBs). It is found that pulse distortion can be restrained by a negative optical control mode when the optical packet is in the loop. Noise analysis indicates that it is feasible to realise a large variable delay range by cascaded DLOBs. These conclusions are validated by the experiment system with 4-stage cascaded DLOBs. Both the theoretical simulations and the experimental results indicate that a large delay range of 1-9999 times the basic delay unit and a fine granularity of 25 ns can be achieved by the cascaded DLOBs. The performance of the cascaded DLOBs is suitable for the all optical networks.