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.     

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.     

Thermal stability and chemical bonding states of AlOxNy/Si gate stacks revealed by synchrotron radiation photoemission spectroscopy

Annealing-temperature dependence of the thermal stability and chemical bonding states of AlO_xN_y/SiO₂/Si gate stacks grown by metalorganic chemical vapor deposition (MOCVD) using new chemistry was investigated by synchrotron radiation photoemission spectroscopy (SRPES). Results have confirmed the formation of the AlN and AlNO compounds in the as-deposited samples. Annealing the AlO_xN_y samples in N₂ ambient in 600-800 °C promotes the formation of SiO₂ component. Meanwhile, there is no formation of Al-O-Si and Al-Si binding states, suggesting no interdiffusion of Al with the Si substrate. A thermally induced reaction between Si and AlO_xN_y to form volatile SiO and Al₂O is suggested to be responsible for the full disappearance of the Al component that accompanies annealing at annealing temperature of 1000 °C. The released N due to the breakage of the Al-N bonding will react with the SiO₂ interfacial layer and lead to the formation of the Si₃-N-O/Si₂-N-O components at the top of Si substrate. These results indicate high temperature processing induced evolution of the interfacial chemistry and application range of AlO_xN_y/Si gate stacks in future CMOS devices.     

Two quantum oscillators coupled with a planar radio frequency ion trap

In this scheme,two quantum oscillators in a planar radio frequency ion trap are coupled by the trap electrodes.The ions motional states encode the quantum bits (qubits),and a swap gate could be achieved.Under different conditions of the experiments,the intensity of the coupling between two quantum oscillators and the dissipation of the system are calculated.We compute fidelities for a quantum swap gate and discuss experimental issues.     

Not-XOR (NXOR) Logic Gate Realized with Enzyme-Catalyzed Reactions: Optical and Electrochemical Signal Transduction

The studied enzyme-based biocatalytic system mimics NXOR Boolean logic gate, which is a logical operator that corresponds to equality in Boolean algebra. It gives the functional value true ( 1 ) if both functional arguments (input signals) have the same logical value ( 0 , 0 or 1 , 1 ), and false ( 0 ) if they are different ( 0 , 1 or 1 , 0 ). The output signal producing reaction is catalyzed by pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH), which is inhibited at acidic and basic pH values. Two other reactions catalyzed by esterase and urease produce acetic acid and ammonium hydroxide, respectively, shifting solution pH from the optimum pH for PQQ-GDH to acidic and basic values ( 1 , 0 and 0 , 1 input combinations, respectively), thus switching the enzyme activity off (output 0 ). When the input signals are not applied ( 0 , 0 combination) or both applied compensating each other ( 1 , 1 combination) the optimum pH is preserved, thus keeping PQQ-GDH running at the high rate (output 1 ). The biocatalytic cascade mimicking the NXOR gate was characterized optically and electrochemically. In the electrochemical experiments the PQQ-GDH enzyme communicated electronically with a conducting electrode support, thus resulting in the electrocatalytic current when signal combinations 0 , 0 and 1 , 1 were applied. The logic gate operation, when it was realized electrochemically, was also extended to the biomolecular release controlled by the gate. The release system included two electrodes, one performing the NXOR gate and another one activated for the release upon electrochemically stimulated alginate hydrogel dissolution. The studied system represents a general approach to the biocatalytic realization of the NXOR logic gate, which can be included in different catalytic cascades mimicking operation of concatenated gates in sophisticated logic circuitries.     

InGaZnO薄膜晶体管背板的栅极驱动电路静电释放失效研究

本文通过解析阵列基板栅极驱动(gate driver on array, GOA)电路中发生静电释放(electro-static discharge,ESD)的InGaZnO薄膜晶体管(InGaZnO thin-film transistor, IGZO TFT)器件发现:栅极Cu金属扩散进入了SiN_x/SiO_2栅极绝缘层;源漏极金属层成膜前就发生了ESD破坏;距离ESD破坏区域越近的IGZO TFT,电流开关比越小,直到源漏极与栅极完全短路.本文综合IGZO TFT器件工艺、GOA区与显示区金属密度比、栅极金属层与绝缘层厚度非均匀性分布等因素,采用ESD器件级分析与系统级分析相结合的方法,提出栅极Cu:SiN_x/SiO_2界面缺陷以及这三层薄膜的厚度非均匀分布是导致GOA电路中沟道宽长比大的IGZO TFT发生ESD失效的关键因素,并针对性地提出了改善方案.     

Λ型三能级原子与两个谐振器的量子相位门

量子纠缠的生成和操控在量子通信和量子信息处理中具有广泛的应用价值.通过构建单个Λ型三能级原子和两个超导谐振器之间相互耦合的模型,给出了实现控制Z门(Controlled-Z)的四种操作方案和实现交换门(Swap)的两种操作方案;同时对实现控制Z门的第一种操作方案进行了保真度的数值模拟仿真.结果表明:通过20.83 ns的运行时间,其保真度为96.67%,而衰减率、弛豫速率和移相比率的增加会降低系统的保真度,而耦合强度的增加会减少系统的运行时间,从而减小衰减参数的影响,提高系统的保真度.     

磁共振成像谱仪B0信号的高精度发生与测试

设计了一种基于现场可编程门阵列（FPGA）的磁共振成像（MRI）谱仪B₀信号的高精度发生方法,并对产生的B₀信号经高速采集卡采集之后进行测试和验证.FPGA从外部读取波形数据和参数,分别存储在双端口随机存取存储器（RAM）和参数寄存器中,根据预补偿算法实现B₀信号的发生,并通过对时间参数和幅度参数的控制,产生不同的B₀信号,时间分辨率为1 μs.对谱仪的B₀输出进行采集,再进行最小二乘拟合,以验证B₀信号发生的准确性.经实验证实,该设计可以产生正确、可控的高精度B₀信号.     

Design and Performance Analysis of High Speed Optical Binary Code Converter using Micro-Ring Resonator

The present paper describes various attractive logical code conversions using optical micro-ring resonator. We have proposed an all-optical switching activity using silicon waveguide based micro-ring resonator under low-power operation through two-photon absorption effect. The different properties of the optical switch are analyzed through numerical simulation. We have also proposed and described all-optical binary-to-octal, binary-coded-decimal-to-excess-3 and binary-to-Gray-code converter circuits by this proposed architecture. Numerical simulation results for code conversion verifying the proposed methods are given in this paper. We identify a combination of feasible ring radius and detuning through numerical simulation that allows analyzing the system performance of the scheme.     

Logical operations using phenyl ring

Exploiting the effects of quantum interference we put forward an idea of designing three primary logic gates, OR, AND and NOT, using a benzene molecule. Under a specific molecule-lead interface geometry, anti-resonant states appear which play the crucial role for AND and NOT operations, while for OR gate no such states are required. Our analysis leads to a possibility of designing logic gates using simple molecular structure which might be significant in the area of molecular electronics.