基于细菌视紫红质光子逻辑门的实验研究

研究了基于细菌视紫红质(简称BR或菌紫质)变种材料D96N的3种光逻辑操作.在633nm激发光照射下，菌紫质分子会被激发到M态，处于M态的菌紫质对412nm的紫光呈较大吸收，会抑制同时入射的紫光.选择合适的紫光强度，通过CCD观测被抑制的412nm检测光透射强度分布，模拟了“非”、“或非”、“与非”几种基本的光子逻辑操作. 关键词： 细菌视紫红质 光子逻辑门 互补抑制     

菌紫质分子膜图象信息存储的实验研究

本文讨论了新型细菌视紫红质基因变种材料的光循环过程及其光致变色特性。利用B态P态之间的光致变色实现信息的存储与读出，建立了细菌视紫红持生物分子膜高分辨图参信息读写实验系统，并在菌紫质分子膜器件上实现了400L／mm高分辨的图象信息存储。     

细菌视紫红质膜非线性吸收特性及其光子学应用

对细菌视紫红质膜在两束非同频光照射下的非线性吸收特性进行了详细的理论分析,并讨论了细菌视紫红质膜非线性吸收特性有光子学方面的一些新应用。     

菌紫质光电作用的分子机制

本文介绍了一种新型的生物分子光电功能材料─-细菌视紫红质,对其结构、光电功能和光化学性质作了简单介绍,着重对其光电作用机理从分子生物学角度进行了阐述,对其在光电器件、神经网络和仿视觉功能系统方面的实际应用给出了几个例子。     

细菌视紫红质膜的光吸收非线性特性研究

对细菌视紫红质（ＢＲ）膜的光学吸收非性进行了研究,分别测量了细菌视紫红质光照前后的光吸收谱,结果显示它的吸收发生了明显的变化。用Ｚ扫描法研究了它的光学非线性,理论计算的结果表明它具有较大的光学非线性系数,且测量它的透过率随光强变化的关系曲线和理论模拟发现它对６３２．８ｎｍ波和匠光具有饱和吸收特性。     

细菌视紫红质膜的光电荷转移 动力学过程的研究

实验测量了细菌视紫红质（bR）分别经波长为1064nm、532nm和355nm,脉冲宽度为10ns的三种不同的脉冲激光照射后产生的不同的光电压信号,着重用532nm脉冲光激发样品,从变化的测量回路的阻抗所得到的不同光电信号情况,研究并分析了细菌视紫红质的光电荷的产生和转移的微观机制。结果表明,其正负脉冲光电压信号是正负两种电荷移动的结果,而正电荷的产生比负电荷的产生和转移的微观机制。结果表明,其正负脉冲光电压信号是正负两种电荷移动的结果,而正电荷的产生比负电荷的产生需要克服更高的能量,同时,正负电荷既具有各自的转移特性又相互影响,如正电荷移动速度慢,负电荷移动速度快,负电荷对正电荷有牵引作用等,这些特性与电极和样品之间形成的界面效应有关,它使得细菌视紫红质的光电压信号的幅值和宽度对外接电阻的关系具有与其他光电响应器件所不同的特性。     

基于菌紫质的光开关原型器件研究

本文分析和讨论了细菌视紫红质的饱和吸收特性及互补抑制特性,在此基础上进行了细菌视紫红质光开关的实验研究。研究证明了被激发到M态的细菌视紫红质分子对紫光有较大的吸收,而处于基态的分子则对黄光有较大吸收。随着入射黄光强度的增加,菌紫质对黄光的吸收呈饱和吸收特必,时菌紫质对紫光呈较大吸收,而较强的紫光照射将会使此饱和吸收阈值增加,使得菌紫质对黄光的吸收又增大,从而黄光和紫光表现出互补透射特性。利用紫光和黄光控制菌紫质分子在M态和基态上的分布,我们实现了对不同的波长光和选通或者关闭,即光开关模型。     

细菌视紫红质生物膜光电探测器

细菌视紫红质是一种光能存储与能量转换的生物膜蛋白质分子在光作用下，参产生极为迅速的电荷分离和蛋白质电响应信号，这种光电信号不同于一般无机光电材料的光电响应特征。用电泳法在ＩＴＯ导电玻璃上沉积出定向细菌视紫红质薄膜，与铜电极构成夹细菌视紫红薄膜和导电凝胶结构的光电探测器。     

细菌视紫红质膜快速光开关的实验研究

建立了“脉冲激光－连续探测光－连续擦除光”的实验系统。在532nm的调Q脉冲激发光和不同波长的连续探测光作用下，研究了细菌视紫红质（BR）膜的光循环过程中的快速响应特性及各中间态的快速光吸收特性。观察到了微秒量级的快速光开关现象，并分析了激发光脉冲作用结束时，各中间态上细菌视紫红质分子的分布。     

细菌视紫红质的光学性质及其光子学应用

文章介绍了新型的生物光学材料－－细菌视紫红质的光学性质及其在光子学领域中的应用，也报道了我们新取得的一些应用成果。     

A novel frequency encoded all optical logic gates exploiting polarization insesensitive four wave mixing in semiconductor optical amplifier, filtering property of ADD/DROP multiplexer and non-linearity of reflective semiconductor amplifier

All optical logic gates exploiting polarization independent four wave mixing in semiconductor optical amplifier (SOA), filtering property of ADD/DROP multiplexer (ADM) and non-linearity in reflective semiconductor optical amplifier (RSOA) have been proposed. The logic gates proposed are polarization independent which ensures hardware simplicity and greater speed. The all optical frequency encoded logic gates NOT, OR, NOR, AND, NAND, X-OR, X-NOR are implemented which are very useful in optical computing ad signal processing, cryptography, etc. The logic gates proposed have the advantages that there is no intensity loss dependent problem, and are polarization and temperature insensitive.     

All optical alternative approach of conducting NAND and NOR logic gates with phase encoding principle

All optical logic gates are the most important building blocks for conducting all optical digital and analog signal processing and computing. It has several uses in the high speed communication system. In last few years various non-linear properties of semiconductor optical amplifier have been utilized for realization of all optical logic gates exploiting different type's optical modulations. In such connection optical phase encoding technique drew more attention in last few years as it shows higher receiver sensitivity and extended tolerance limit in long-haul fiber transmission systems. In this communication the authors have proposed an alternative approach for conducting all optical logic gates with phase encoded inputs by the exploitation of the four wave mixing (FWM) property in semiconductor optical amplifier (SOA).     

All optical method of developing OR and NAND logic system based on nonlinear optical fiber couplers

Logic gates are the fundamental building blocks in any digital data processing system. Several all optical logic operations are already proposed by scientists and technologists. Here the authors proposed a new method of all optical logic operation based on nonlinear directional coupler. Effective optical switching is achieved by modifying the coupling length between the coupler waveguides by means of an optical signal.     

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.     

Simulation of two photon absorption in silicon wire waveguide for implementation of all optical logic gates

All optical switching action of silicon wire waveguide for the design of the proposed logic gates is simulated. This is one possible building block of the future all optical computer or photonic devices. All optical logic gates NOT, NAND and AND gates using two photon absorption in silicon wire waveguide are presented. Use of ultra short pulse has negligible free carrier absorption effect; hence the operating speed of the gates is very high and has potential application in photonic processing. NAND gate is universal one and thus one can perform any logical operation using this. The device (Si wire WG) requires low energy pulse and is ultrafast one.     

Universal quantum logic gates in decoherence-free subspace with atoms trapped in distant cavities

We propose a scheme for implementation of a universal set of quantum logic gates in decoherence-free subspace with atoms trapped in distant cavities connected by optical fibers.The selective dispersive couplings between the ground states and the first-excited states of the atom-cavity-fiber system produce a state-dependent Stark shift,which can be used to implement nonlocal phase gates between two logic qubits.The single-logic-qubit quantum gates are achieved by the local two-atom collision and the Stark shift of a single atom.During all the logic operations,the logic qubits remain in decoherence-free subspace and thus the operation is immune to collective dephasing.     

基于非线性光纤环镜的40Gb/s可重构光逻辑门

提出了一种新型的基于非线性光纤环镜(NOLM)的可重构全光逻辑门实现方案。传统的基于NOLM的全光逻辑利用自相位调制效应或交叉相位调制效应,透射传输函数重构的自由度低,可实现的逻辑门种类较少。该方案在传统的结构基础上,分析了NOLM中探测光的偏振态的演化,以及输入光偏振态和环内偏振控制器对NOLM的传输特性的影响。理论分析和数值仿真结果表明在考虑NOLM中的非线性偏振旋转效应的情况下,可以更加自由地构建不同透射传输函数,从而利用单一NOLM结构,仅通过调节偏振控制器,即能够可重构地实现绝大部分基础组合逻辑。实验中,完成了两路40Gb/s的数据信号之间的"非"、"与"、"或"、"或非"、"同或"、"异或"等各种基础组合逻辑,验证了方案的可行性。     

All-Optical Multifunctional Logic Gates for Image Information Using Photorefractive Two-Wave Mixing

In this paper, we propose all-optical multifunctional logic gates for image information using photorefractive (PR) two-wave mixing. The optical setup is simply configured compared with the other all-optical logic gates for image information. The XOR-, OR-, and AND-operation are all-optically performed in the same optical setup through the transitional response of the PR medium. One can switch these logic operations simply by means of the on-off control of the signal and the pump beam illumination. We analyze the spatial distribution of beam intensity in these logic gates using a finite-difference beam propagation method (FD-BPM) and the crosstalk between adjoining pixels is examined from the result. We also experimentally verify that the XOR-, OR-, and AND-gates are realized in the same optical setup.