激光混沌并联同步及其在全光逻辑门中的应用研究

提出多量子阱激光器混沌“主-从-响应”式结构同步系统,研究其并联同步在光学逻辑门中的应用. 利用一个注入多量子阱激光器混沌系统注入驱动实现了两个响应多量子阱激光系统的混沌并联同步,同时还获得了“主-从”式结构的混沌同步. 基于响应子系统的混沌并联同步思想,提出了全光逻辑门的基本理论模型并定义了计算原则与方法. 利用光的外部调制方法对两个驱动光进行调制与控制,让两个响应子系统实现同步与非同步,使系统获得了并具有全光逻辑门函数功能与特点,并成功地进行了数字逻辑计算. 具体提出了全光XNOR、NOR、NOT等逻辑门及逻辑计算方法,数值模拟结果证明了系统方案的可行性. 关键词： 混沌 同步 逻辑门 多量子激光器     

Controllable all-optical stochastic logic gates and their delay storages based on the cascaded VCSELs with optical-injection

Using the dynamical properties of the polarization bistability that depends on the detuning of the injected light,we propose a novel approach to implement reliable all-optical stochastic logic gates in the cascaded vertical cavity surface emitting lasers(VCSELs) with optical-injection.Here,two logic inputs are encoded in the detuning of the injected light from a tunable CW laser.The logic outputs are decoded from the two orthogonal polarization lights emitted from the optically injected VCSELs.For the same logic inputs,under electro-optic modulation,we perform various digital signal processing(NOT,AND,NAND,XOR,XNOR,OR,NOR) in the all-optical domain by controlling the logic operation of the applied electric field.Also we explore their delay storages by using the mechanism of the generalized chaotic synchronization.To quantify the reliabilities of these logic gates,we further demonstrate their success probabilities.     

Chaotic synchronization of two inverse-injection semiconductor lasers for logic gates

A round-coupling configuration of two inverse-injection semiconductor lasers is presented for logic gate applications. Two laser diodes coupled via injection from the opposite laser became chaotic. Chaotic synchronization is achieved between the two lasers. Two all-optical or two optoelectronic logic gates can be implemented by modulating the injected light or laser diode current, respectively, to synchronize or unsynchronize the two chaotic states. Numerical results show the validity and feasibility of the method.     

Reconfigurable all-optical logic gate using four-wave mixing (FWM) in HNLF for NRZ-PolSK signal

We demonstrate a reconfigurable all-optical logic gate for NRZ-PolSK signal based on FWM in a highly nonlinear fiber at 10 Gb/s. Half subtracter, XOR, AB?, āB or XNOR, AND, and NOR logic gates can be implemented simultaneously. The input power for the HNLF is optimized to be as low as about 15.2 dBm and the high Q factors above 8 dB for eye diagrams are achieved. Experimental results show Q factors of AB?, āB, AND, and NOR were higher than those of XOR, and XNOR. Error-free operation is achieved experimentally for 10 Gb/s 2⁷-1 pseudorandom bit sequence (PRBS) data. Power penalties for the logic gate are less than 3 dB. Simulation analysis about the wavelength characteristic for all logic gates is given and it predicts that the reconfigurable logic gate can realize error-free operation when the wavelength separation is less than 5 nm.     

激光混沌耦合反馈光电及全光逻辑门研究

理论上利用两个混沌半导体激光器的耦合反馈,构建了两种基本的光电及全光门.基本方法是,让外部光注入到两个激光器中而导致激光混沌,通过两激光器激光的相互耦合及反馈实现同步;在这基础上,一是让两激光器分别在电流调制下,控制混沌同步或者非同步,实现光电逻辑门的功能与计算;二是利用光的外部调制方法让两相互耦合激光分别在相位调制下,控制混沌同步或者非同步,并最终实现全光逻辑门的功能与计算.数值结果证明了两方法的可行性. 关键词： 混沌 逻辑门 激光器 同步     

Realization of morphing logic gates in a repressilator with quorum sensing feedback

We demonstrate how a genetic ring oscillator network with quorum sensing feedback can operate as a robust logic gate. Specifically we show how a range of logic functions, namely AND/NAND, OR/NOR and XOR/XNOR, can be realized by the system, thus yielding a versatile unit that can morph between different logic operations. We further demonstrate the capacity of this system to yield complementary logic operations in parallel. Our results then indicate the computing potential of this biological system, and may lead to bio-inspired computing devices.     

Realization of XNOR logic function with all-optical high contrast XOR and NOT gates

In this article, we propose the realization of XNOR logic function by using all-optical XOR and NOT logic gates. Initially, both XOR and NOT gates are designed, simulated and optimized for high contrast outputs. T-shaped waveguides are created on the photonic crystal platform to realize these logic gates. An extra input is used to perform the inversion operation in the NOT gate. Inputs in both the gates are applied with out of phase so as to have a destructive interference between them and produce negligible intensity for logic ‘0'. The XOR and NOT gates are simulated using Finite Difference Time Domain method which results with a high contrast ratio of 55.23?dB and 54.83?dB, respectively at a response time of 0.136?ps and 0.1256?ps. Later, both the gates are cascaded by superimposing the output branch of the waveguide of XOR gate with the input branch of the waveguide of NOT gate so that it can be resulted with compact size for XNOR logic function. The resultant structure of XNOR logic came out with the contrast ratio of 12.27?dB at a response time of 0.1588?ps. Finally, it can be concluded that the proposed structures with fair output performance can suitably be applied in the design of photonic integrated circuits for high speed computing and telecommunication systems.     

Implementing logic gates and the Deutsch-Jozsa quantum algorithm by two-dimensional NMR using spin- and transition-selective pulses

Quantum logical operations using two-dimensional NMR have recently been described using the scalar coupling evolution technique [J. Chem. Phys. 109, 10603 (1998)]. In the present paper, we describe the implementation of quantum logical operations using two-dimensional NMR, with the help of spin- and transition-selective pulses. A number of logic gates are implemented using two and three qubits with one extra observer spin. Some many-in-one gates (or Portmanteau gates) are also implemented. Toffoli gate (or AND/NAND gate) and OR/NOR gates are implemented on three qubits. The Deutsch-Jozsa quantum algorithm for one and two qubits, using one extra work qubit, has also been implemented using spin- and transition-selective pulses after creating a coherent superposition state in the two-dimensional methodology.     

Ultra high-speed optical signal processing based on single SOA at 60 Gb/s

The paper shows the design of all-optical logic gates OR, AND, NOT, NOR, XNOR, XOR at ultra high speed by using SOA. The simulations of all logic gates are obtained by XGM and FWM in SOA at 40 Gb/s and 60 Gb/s. The OR, AND, NOR logic between two data sources are obtained using a pump signal, while another logic XNOR using two data. The NOT, XOR obtained using FWM and XGM combined. Thus realization of these logics at 40 Gb/s and 60 Gb/s will lead revolution growth in optical signal processing for high-speed operation.     

Logic from nonlinear dynamical evolution

We propose a direct and flexible implementation of logic operations using the dynamical evolution of a nonlinear system. The concept involves the observation of the state of the system at different times to obtain different logic outputs. We explicitly implement the basic NAND, AND, NOR, OR and XOR logic gates, as well as multiple-input XOR and XNOR logic gates. Further we demonstrate how the single dynamical system can do more complex operations such as bit-by-bit addition in just a few iterations.     

飞秒激光直写光量子逻辑门

量子比特在同一时刻可处于所有可能状态上的叠加特性使得量子计算机具有天然的并行计算能力,在处理某些特定问题时具有超越经典计算机的明显优势.飞秒激光直写技术因其具有单步骤高效加工真三维光波导回路的能力,在制备通用型集成光量子计算机的基本单元—量子逻辑门中发挥着越来越重要的作用.本文综述了飞秒激光直写由定向耦合器构成的光量子比特逻辑门的进展.主要包括定向耦合器的功能、构成、直写和性能表征,集成波片、哈达玛门和泡利交换门等单量子比特逻辑门、受控非门和受控相位门等两量子比特逻辑门的直写加工,并对飞秒激光加工三量子比特逻辑门进行了展望.     

Multiple-output logic element based on an optical interference system

A multiple-output logic element using an optical interference system is proposed. The system acts as a logic gate array operating in parallel at certain positions divided over one period of the output fringe. A photoinduced refractive-index change material is incorporated in the system to perform the optical transformation of optical inputs into the phase change of a readout beam. It is shown that the logic gates obtained can be controlled arbitrarily in number and sorts by adjusting either the shift or the division of the output fringe. As an example, logic gates of AND, OR, NAND, NOR are implemented in parallel in the preliminary experiments.     

Computational analysis of solitons all-optical logic NAND and XNOR gates using semiconductor optical amplifiers

Solitons all-optical logic NAND and XNOR gates using semiconductor optical amplifiers-assisted Mach–Zehnder interferometers are computationally analyzed at a data rate of 80 Gb/s. The investigation of the output quality factor is included. All-optical logic gates are capable of operating at 80 Gb/s with logical correctness and acceptable quality.     

Bio-inspired computation using synthetic genetic network

Potential of synthetic genetic network, Repressilator, to work as logical computing unit is observed. It is shown that two variables of gene network yield simultaneously, the basic AND or OR gate with their complementary NAND or NOR gate, with the variation of the internal parameter of the system. This allows the gene network to work as a strong candidate for parallel computing. Stability or robustness of gates is also checked in noisy background.     

Computing with distributed chaos

We describe and discuss in detail some recent results by Sinha and Ditto [Phys. Rev. Lett. 81, 2156 (1998)] demonstrating the capacity of a lattice of threshold coupled chaotic maps to perform computations. Such systems are shown to emulate logic gates, encode numbers, and perform specific arithmetic operations, such as addition and multiplication, as well as yield more specialized operations such as the calculation of the least common multiplier of a sequence of numbers. Furthermore, we extend the scheme to multidimensional continuous time dynamics, in particular to a system relevant to chaotic lasers.     

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.     

基于单个半导体光放大器的高速多功能逻辑门

采用半导体光放大器(SOA)中的非线性效应可以实现多种多样的高速全光信号处理. 利用SOA的非线性效应(包括四波混频、交叉增益调制、瞬态交叉相位调制等)实现了多种功能的逻辑运算,包括“与”、“或非”、“同或”、“或”和“非”. 由于SOA用于全光信号处理的调制速率受到增益恢复时间较慢的限制而无法实现高速的信号处理,在SOA后面级联一个带宽为0.32nm的失谐滤波器可以提高SOA的工作速率,仅用一个SOA实现了40Gbit/s的多功能逻辑门. 关键词： 半导体光放大器 全光逻辑门 瞬态交叉相位调制     

Silicon photonic crystal all-optical logic gates

All-optical logic gates, including OR, XOR, NOT, XNOR, and NAND gates, are realized theoretically in a two-dimensional silicon photonic crystal using the light beam interference effect. The ingenious photonic crystal waveguide component design, the precisely controlled optical path difference, and the elaborate device configuration ensure the simultaneous realization of five types of logic gate with low-power and a contrast ratio between the logic states of “1” and “0” as high as 20 dB. High power is not necessary for operation of these logic gate devices. This offers a simple and effective approach for the realization of integrated all-optical logic devices.     

All optical NOR and NAND gate based on nonlinear photonic crystal ring resonators

In this paper we proposed optical NOR and NAND gates. By combining nonlinear Kerr effect with photonic crystal ring resonators first we designed a structure, whose optical behavior can be controlled via input power intensity. The switching power threshold obtained for this structure equal to 2 kW/μm². For designing the proposed optical logic gates we employed two resonant rings with the same structures, both rings at the logic gates were designed such that their resonant wavelength be at λ = 1550 nm. Every proposed logic gate has one bias and two logic input ports. We used plane wave expansion and finite difference time domain methods for analyzing the proposed structures.     

Reconfigurable dynamic all-optical chaotic logic operations in an optically injected VCSEL

In a chaotic system of vertical cavity surface emitting laser(VCSEL) with external optical-injection, we propose a novel implementation scheme for reconfigurable dynamic all-optical chaotic logic operations(AOCLOs). Under different key parameters, such as the bias current, the injection strength and the frequency detuning of the injected light field and the VCSEL, we also explore the evolutions of the polarization-bistability with the amplitude of the injected light field when the output of VCSEL is chaotic wave. According to the dynamic evolutions, we find out the optimal value of the frequency detuning that is considered as a control logic signal, and further implement different AOCLOs, such as AND, NAND, OR,NOR, XOR, and XNOR, by controlling the logic operation of the control logic signal between two logic inputs. Moreover,the ability to reconstruct these logic operations is demonstrated under relatively low noise strength of the spontaneous emission.