Mach-Zehnder interferometer-based tree architecture for all-optical logic and arithmetic operations

Interferometric devices for optical processing have been of great interest in recent years. Semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI) has already taken a significant role in the field of ultra-fast all-optical signal processing. Optical tree architecture (OTA) provides important contributions in optical interconnecting networks. In this communication, we have tried to exploit the advantages of both OTA and SOA-based MZI switches. We have proposed SOA-MZI-based tree architecture, a new and alternative scheme, for integrated all-optical logic and arithmetic operations. This architecture can enable one to perform all-optical processing of signals, including two input logic operations, half-adder, full-adder, full-subtractor, one-bit data comparator, etc.     

Ultrafast all-optical XOR logic gate based on a symmetrical Mach-Zehnder interferometer employing SOI waveguides

We present an integrated Silicon-on-Insulator (SOI) based Mach-Zehnder interferometer (MZI) in order to perform ultrafast all-optical XOR logic gate operation with a bit rate of ∼ 0.33 Tb/s. A numerical simulation is carried out in order to study various parameters such as extinction ratio and eye-opening parameters, characterizing the performance of the XOR logic gate. The output XOR logic gate signal can have improved extinction and eye margin if the initial powers of primary signals and the probe continuous-wave (CW), and SOI waveguide length are judiciously adjusted.     

Improved all-optical modified signed-digit adders using semiconductor optical amplifier and Mach-Zehnder interferometer

In this paper, we present improved all-optical circuits that implement ultra-fast adders based on the carry-free property of the modified signed-digit (MSD) number representation. The all-optical realizations are based on semiconductor optical amplifier (SOA) and Mach-Zehnder interferometer (MZI) switches, which represent one of the most promising solutions due to their compact size, thermal stability and low power operation. Several all-optical circuit designs are proposed with the objective to minimize the number of the SOA-MZI switches, the time delay in the adders and some other optical elements. The proposed circuits are more efficient comparing to previously published ones in terms of the number of optical components (less by 50%) as well as the operational speed (faster by 50%).     

Design of SOA-MZI based all-optical programmable logic device (PLD)

Photon being the ultimate unit of information with unmatched speed and with data package in a signal of zero mass, the techniques of computing with light may provide a way out of the limitations of computational speed and complexity inherent in electronics computing. Information processing with photon as information carrying signal has shown a high level potentiality through the researches in last few decades. The driving force behind this evolution has been the utilization of interferometric configurations that employ a semiconductor optical amplifier (SOA) as the nonlinear element in combination with cross-phase modulation to achieve switching by means of light. Here, in this paper we present an all-optical circuit of programmable logic device (PLD) with the help of SOA-MZI (Mach-Zehnder interferometer) based optical tree-structured splitter. Numerical simulation result confirming described method is reported here. This paper also explains the applicability of this scheme to perform logical and arithmetic operations in all-optical domain.     

Effect of amplified spontaneous emission on semiconductor optical amplifier based all-optical logic

The performances of all-optical logic gates XOR, AND, OR, NOR and NAND based on semiconductor optical amplifier (SOA) have been simulated including the effects of amplified spontaneous emission (ASE). For the parameters used, all-optical logic gates using SOA are capable of operating at speed of 80 Gb/s.     

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.     

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.     

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.     

All-fiber Mach-Zehnder interferometer for DWDM filter direct group-delay measurement

The group delay of the dense wavelength division multiplexing (DWDM) filter is becoming more important in optical communication. This study proposes a Mach-Zehnder interferometer based on the direct group delay measurement of an optical thin film filter. The interferometer provides a simple, accurate and physically intuitive picture of what happens to broadband optical pulses on common optical materials. A 100 GHz DWDM filter was used as an example in the measurement and showed that the time of measurement and selection of Gaussian window were two important factors.     

Multi-ion Mach–Zehnder interferometer with artificial nonlinear interactions

We propose a method to implement a Mach-Zehnder interferometry based upon a string of trapped ions with artificial nonlinear interactions. By manipulating the coupling strength between two involved internal states of the ions, we could achieve the beam splitting/recombination with NOON states. Using current techniques for manipulating trapped ions, we discuss the experimental feasibility of our scheme and analyze some undesired uncertainty under realistic experimental environment.     

孔型硅光子晶体中折叠式马赫-曾德尔干涉仪(英文)

设计了基于孔型硅光子晶体的折叠式马赫-曾德尔干涉仪.它由一个光反射器和几个光分束器构成.在干涉仪中,窄光束依赖自准直效应进行传输.利用时域有限差分法研究了折叠式马赫-曾德尔干涉仪的特性.结果表明,在0.255～0.270c/a的归一化频率范围内,干涉仪的两个透射谱均为正弦形且强度互补,透射谱的透射峰间距随着干涉仪两臂的光程差的增大而减小.该折叠式干涉仪结构紧凑,尺寸比非折叠式光子晶体马赫-曾德尔干涉仪要小许多,有望作为信道解复用器应用于光子芯片中.     

Design of an ultrafast all-optical NOR logic gate based on Mach-Zehnder interferometer using quantum-dot SOA

This paper proposes a design for all-optical NOR logic gate, based on Mach-Zehnder interferometer (MZI) using quantum-dot semiconductor optical amplifier (QD-SOA). In this regard, a theoretical model for an ultrafast all-optical signal processor is developed using QD-SOA to achieve high bit rate operation. We have demonstrated the NOR gate operation in two cases of with and without an optical control pulse. Simulations have been carried out at data bit rates 160 Gb/s, 200 Gb/s, and 250 Gb/s for the case that control pulse is not applied, and also at data bit rates 1 Tb/s and 2 Tb/s in presence of control pulse which leads to improvement of gain recovery time and ultrafast NOR logic operation. In addition, quality factors of the output signals in presence and without the control pulse at different bit rates with different bias currents have been investigated for pseudo-random binary sequence (PRBS) of word length 2⁸–1.     

Distributed fiber-optic vibration sensor using a ring Mach-Zehnder interferometer

A novel distributed fiber-optic vibration sensing system is proposed and demonstrated. By employing a ring Mach-Zehnder interferometer (MZI) structure as the sensing section, both position and frequency can be determined by combining two phase signals from the ring configuration. A spatial resolution better than 38 m is successfully verified in a 1.01 km prototype system of single vibration. Moreover, the feasibility of separately locating multiple vibrations is also theoretically simulated and experimentally investigated.     

耦合环形腔马赫-曾德尔干涉仪瞬态响应及应用

对耦合环形腔马赫-曾德尔干涉仪光脉冲瞬态响应进行了理论和数值研究.利用光束追迹法推导了脉冲传输的解析关系,并数值模拟了传输光场随时间的演化.输出脉冲形状可通过控制损耗进行调解,响应速度为皮秒量级.由于马赫-曾德尔干涉仪两输出端口的互补性,在输出端可同时实现光脉冲微分和积分操作.利用损耗控制机制,可实现单通道脉冲微分和积分操作转换.引入增益补偿损耗,可实现脉冲压缩及产生可调单一触发光脉冲.     

All-optical logic OR gate using SOA and delayed interferometer

All-optical OR operation has been demonstrated using a semiconductor optical amplifier (SOA) and delayed interferometer (DI) at 80 Gb/s. The DI is based on a polarization maintaining loop mirror. Q-factor of the operation is discussed through numerical simulations. The results show the OR gate operation rate is limited by the gain recovery time and input pulse energy.     

光纤马赫—陈德尔干涉型8波分超窄波分复用器的研制

报道了采用７个单模光纤马赫－陈德尔干涉仪进行三级串联而组成的８波分复用器，既保留了干涉型光纤波分复用器超窄波分复用间隔的优点，又消除了其复用路数少的缺点。文中介绍了这类波分复用器的原理、设计方法和制造技术。实验样品的使用波段为１．５μｍ，波长复用间隔为２．４ｎｍ，整个器件的附加损耗约为１．５ｄＢ。     

光纤Mach-Zehnder空间干涉系统的实验研究

深入细致地分析和研究光纤Mach-Zehnder空间干涉系统,详细介绍了各组成部分及功能,并对空间干涉场进行了理论分析,得到了线偏振光输出下的干涉场理论表达式和干涉场图。     

复合材料分层检测用光纤Mach-Zehnder干涉仪

发展了一种能够有效检测复合材料分层的光纤Mach Zehnder干涉仪。用一只2×2耦合器和一只3×3耦合器构成光纤干涉仪,输出信号经A/D转换后送入计算机,用软件进行信号解调。将此干涉仪的一个臂埋入材料内部或粘贴在复合材料表面,沿光纤逐点下压材料,通过光纤干涉仪测量出传感光纤形变的大小和方向,这样就能够有效的检测出材料内部是否存在分层。     

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.     

Tilting and shearing determination in the alignment of a Mach-Zehnder interferometer by zone plates

An easy and accurate method to detect the kind of disarrangement and its magnitude in the adjustment process of a Mach-Zehnder interfermeter by means of an equilateral hyperbolic zone plate is explained.