共查询到18条相似文献,搜索用时 794 毫秒
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细菌视紫红质(bacteriorhodopsin,简称BR)是嗜盐菌细胞膜内的一种光敏蛋白质。BR薄膜材料具有优异的光循环特性和光致变色特性,可作为信息存储材料。本文讨论了BR所记录图像的对比度与读出光波长变化之间的关系。实验中利用YAG激光器二倍频532nm激光作为图像记录光,白光光源通过单色仪选出单色光作为图像读出光,观察BR膜所记录图像对比度随读出光波长变化趋势,并利用图像灰度积分的方法得到记录图像对比度变化曲线。读出光在470nm-620nm波长范围内,读出为正像;460nm波长附近,图像消失;380nm-450nm波长范围内,图像出现反转。 相似文献
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实时图像边缘增强空间光调制器 总被引:1,自引:1,他引:0
光学相关识别中首先需要一个把非相干到相干光进行转换的输入图像转换器,然后,再进入输入图像的边缘增强预处理,我们研制的光寻址单晶硅液晶光阀能够同时完成这两项功能。给出图像边缘增强的实验结果。 相似文献
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野生型细菌视紫红质薄膜光谱响应特性的实验研究 总被引:1,自引:0,他引:1
细菌视紫红质 (Bacteriorhodopsin ,简称BR)是嗜盐菌细胞膜内的一种光敏蛋白质。BR薄膜材料具有优异的光循环特性和光致变色特性 ,在光信息处理领域中有广阔的应用前景。文章通过紫外 可见光光纤光谱仪测试野生型细菌视紫红质 (BRWT)在经过 5 32nm的YAG激光的泵浦激励后 ,薄膜对探测光的吸收光谱变化情况来着重讨论BRWT的光谱响应特性。采用的样品基态 (B态 )最大吸收波长均为 5 6 2nm ,光密度分别为OD(WT1) 562nm=2 0 4 ,OD(WT2 ) 562nm =1 37。实验结果表明 ,在 5 5 0~ 6 5 0nm波长范围内 ,两个BRWT分子膜对探测光随着探测时间的延长均出现吸收增强的现象。利用双e指数曲线拟合方法分析出 5 5 0~ 6 5 0nm吸收增强的变化过程分为快过程和慢过程 ,其对应的时间常数BRWT1分别约为 11ms和 6 0s ,BRWT2 分别约为 2 4ms和 35s。 相似文献
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菌紫质光致变色吸收特性的二能级理论研究 总被引:3,自引:2,他引:1
采用二能级模型(B态和M态)简化菌紫质(bR)光循环过程,建立了菌紫质光致变色吸收特性的数学方程,数值计算了bR膜对570nm单光束和对570nm与412nm双光束的吸收特性.计算表明,bR膜的光吸收特性与入射光波长、入射光强、摩尔消光系数、光密度和M态寿命有很大的关系.bR膜用于光存储时,读出光强和M态寿命是影响bR读出使用时间的两个重要因素.570nm与412nm双光束作用于bR膜时,可以实现以光控光操作,但由于570nm黄光的透过动态范围要比412nm紫光的透过动态范围大得多,因而在实际应用中应以黄光作为信息光,紫光作为控制光.基于bR膜对黄、紫光束的吸收特性,可以将其应用于亮背景滤除、反象器、图象相减、光寻址空间光调制器等光信息处理领域. 相似文献
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基于相干密度理论,数值地研究了在饱和对数非线性介质中多个部分非相干光空间孤子之间的相互作用. 数值结果表明,在非相干参量较小情况下,非相干光孤子的相互作用与相干光孤子的相互作用规律较类似. 当非相干参量较大时,强的非相干性模糊了孤子之间的相位关系,孤子间的相互作用主要以非相干相互吸引作用为主. 特别是在非相干参量较大而且孤子初始相对相位差为π的情况下,多个部分非相干光孤子可并行传播形成稳定的阵列孤子. 利用多个非相干光孤子的不同相互作用形态写入各种阵列波导,为实现光控制光、导向光提供了一种可能性.
关键词:
多个部分非相干光空间孤子
空间光孤子的相互作用
相干密度理论
饱和对数非线性 相似文献
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LED照明的光栅光调制器光学特性分析与实验 总被引:2,自引:1,他引:1
针对一种新型的光凋制器--光栅光调制器,研究用LED作为其照明光源时对光学调制特性的影响.以部分相干光理论为依据,结合MATLAB仿真,推导出用LED照明光栅光调制器时,光源带宽对成像对比度具有较大的影响,通过滤色片将光源带宽减小到13 nm时,像面上的对比度约为150,进一步减小带宽至10 nm,对比度将达到225.光源的尺寸在与光源到光栅光调制器之间的距离相比小于0.03时,对光栅光调制器的光学信息处理不会有影响,并通过实验加以证实,从而说明采用LED作为光栅光调制器照明光源的可行性. 相似文献
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BR-D96N is a kind of genetically site-specific mutant of bacteriorhodopsin (BR) with obvious photochromic effect. Compared to the wild type BR, the lifetime of M state of BR-D96N is prolonged to several minutes so that the photochromic kinetics and the intermediates formation can be studied by the conventional spectra analysis. In the experiment, the absorption spectra of the sample at different time after light illumination are measured with spectrophotometer. By fitting and analyzing the variation of the spectra, we suppose there are three main states in the photochromic process, i.e. B state (light-adapted state), M state and D state (dark-adapted state). The absorption spectra of the B state, M state and D state are extracted from the experimental data based on this three-state model and the spectra at various time are fitted with the least square method. So, the variations of population percentages of the M state, B state and D state are obtained and the M state and B state lifetimes are estimated. In another way, from measuring the absorption dynamics at 407 nm and 568 nm, the M state and B state lifetimes are also obtained by two exponential data fitting, which give coincident results with those of the spectra analysis. 相似文献
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Incoherent optical processing with films made from the biological photochrome bacteriorhodopsin (BR) is accomplished by use of the photoinducible anisotropy of polymeric BR films. BR has two spectrally well separated states, B and M, both of which show a high degree of optical anisotropy. Whereas with green and blue light the BR molecule can be switched between the two states, the accompanying changes in the refractive index may be nondestructively read out by wavelengths in the red, e.g., at 676nm. As the sensitivity of CCD arrays is quite high for such wavelengths, even low-power light sources are sufficient for detection. We describe a BR-based XOR computing module for incoherent optical data processing. 相似文献
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陈云华 《中国物理C(英文版)》2020,(2):42-50
We study the contributions of intermediate bottomonium-like Zb states and the bottom meson loops in the heavy quark spin flip transitionsγ(4 S)→hb(1 P,2 P)π+π-.Depending on the constructive or destructive interferences between the Zb-exchange and the bottom meson loops mechanisms,we predict two possible branching ratios for each process:BRγ(4 S)→hb(1 P)π+π-≈(1.20.40.8×10^-6)or(0.5-0.20.5×10^-6),and BRγ(4 S)→(2 P)π+π-≈(7.1-1.1+1.7×10^-10)or(2.4-0.10.2×10^-10)).The contribution of the bottom meson loops is found to be considerably larger than that of the Zbexchange in the T(4 S)→hb(1 P)ππtransitions,while its decay rates are not comparable to those of heavy quark spin conservedγ(4 S)→γ(1 S,2 S)ππprocesses.We also predict the contribution of the charm meson loops in the branch fractions ofΨ(3 S,4 S)→hc(1 P)ππ. 相似文献
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In polymeric films of bacteriorhodopsin (BR) a photoconversion product, which was named the F620 state, was observed on excitation of the film with 532 nm nanosecond laser pulses. This photoproduct shows a strong nonlinear absorption. Such BR films can be used for write-once-read-many (WORM) optical data storage. We demonstrate that a photoproduct similar or even identical to that obtained with nanosecond pulses is generated on excitation with 532 nm femtosecond pulses. This photoproduct also shows strong anisotropic absorption, which facilitates polarization storage of data. The product is thermally stable and is irretrievable to the initial B state either by photochemical reaction or through a thermal pathway. The experimental results indicate that the product is formed by a two-photon absorption process. Optical WORM storage is demonstrated by use of two polarization states, but more polarization states may be used. The combination of polarization data multiplexing and extremely short recording time in the femtosecond range enables very high data volumes to be stored within a very short time. 相似文献
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Influence of Zr(50)Cu(50) thin film metallic glass as buffer layer on the structural and optoelectrical properties of AZO films 下载免费PDF全文
Aluminum-doped ZnO(AZO) thin films with thin film metallic glass of Zr(50)Cu(50) as buffer are prepared on glass substrates by the pulsed laser deposition. The influence of buffer thickness and substrate temperature on structural, optical, and electrical properties of AZO thin film are investigated. Increasing the thickness of buffer layer and substrate temperature can both promote the transformation of AZO from amorphous to crystalline structure, while they show(100)and(002) unique preferential orientations, respectively. After inserting Zr(50)Cu(50) layer between the glass substrate and AZO film, the sheet resistance and visible transmittance decrease, but the infrared transmittance increases. With substrate temperature increasing from 25℃ to 520℃, the sheet resistance of AZO(100 nm)/Zr(50)Cu(50)(4 nm) film first increases and then decreases, and the infrared transmittance is improved. The AZO(100 nm)/Zr(50)Cu(50)(4 nm) film deposited at a substrate temperature of 360℃ exhibits a low sheet resistance of 26.7 ?/, high transmittance of 82.1% in the visible light region, 81.6% in near-infrared region, and low surface roughness of 0.85 nm, which are useful properties for their potential applications in tandem solar cell and infrared technology. 相似文献
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用脉冲激光沉积(PLD)的方法在多孔硅衬底上沉积了ZnS薄膜,并在室温下研究了ZnS/PS异质结的结构、光学和电学性质。X射线衍射仪(XRD)测量结果表明.制备的ZnS薄膜在28.5°附近有一较强的衍射峰,对应于β-ZnS(111)晶向,说明薄膜沿该方向高度择优取向生长。ZnS/PS复合体系的光致发光谱表明,ZnS的发光与PS的发光叠加在一起,在可见光区形成一个450-700nm较宽的光致发光谱带。呈现较强的白光发射。对ZnS/PS异质结I-V,特性曲线的测量结果表明,异质结呈现出与普通二极管相似的整流特性。在正向偏置下,电流密度较大.电压降较低;在反向偏置下,电流密度接近于零。异质结的理想因子的值为77。 相似文献