共查询到20条相似文献,搜索用时 15 毫秒
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Lianlai Sun Xuan Luo Shufan Chen Yu Fang Qingjun Zhang Linhong Cao 《Journal of Macromolecular Science: Physics》2015,54(7):811-822
The optical properties of several carbazole-based photorefractive polymers which we prepared were determined. Through analysis of the UV-vis spectrum, the ratio of the azo nitrobenzene was adjusted to control the content of azo chromophore functional components. The solid transient fluorescence emission spectra of the photorefractive polymers were tested with a 325 nm emission wavelength. The results showed that the J-aggregates and several large closed-loop structures formed in the photorefractive polymers resulted in a long lifetime of their transient fluorescence. Spin-orbit coupling among the molecules increased the intersystem crossing rate, and induced delayed fluorescence. 相似文献
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研究了掺杂CdS纳米粒子的有机聚合物体系的光折变效应,体系中以CdS纳米粒子为光敏剂,聚乙烯咔唑(PVK)为载流子输运剂,4-(4-硝基苯偶氮)苯胺染料(DO3)为非线性生色团,9-乙基咔唑(ECZ)为增塑剂。反胶束法合成的CdS胶束颗粒采用紫外可见吸收光谱和透射电子显微镜(TEM)表征,结果表明,具有纳米尺寸和量子限制效应。研究了PVK-CdS薄膜的光电导特性,实验结果表明,CdS纳米粒子与PVK之间的电荷转移可以有效的提高PVK的光电导率。双光束耦合实验证明了该体系的光折变特性,在无外加电场下,获得二波耦合增益系数78.4 cm-1,分析表明聚合物薄膜具有强的光致取向增强效应;样品在两相干光束作用下,可建立折射率光栅,其衍射效率达到4.4%。 相似文献
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合成了新型偶氮分子偶氮二苯胺ADPA(Azo-diphenylamine),将其掺入聚乙烯咔唑Poly(N-Vinylcarba-zole)(PVK)和聚丙烯丁酯(Poly-butylacrylate)(PBA)的聚合物(PVK-PBA)以及三硝基芴酮2,4,7-trinitro-9-flu-orenone(TNF)聚合制成薄膜器件。结果表明掺杂偶氮苯聚合物薄膜在非共振吸收下具有强的光致取向增强光折变效应。光致折射率变化值Δn达到1.3×10-3以上。样品在两相干光束作用下,可建立光折射率光栅,其衍射效率可超过30%,实现了光全息存储。讨论了影响折射率光栅的因素,并对全息存储相关结果形成的机制进行了分析。 相似文献
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Daisuke Ishikawa Atsushi Okamoto Satoshi Honma Terumasa Ito Kohei Shimayabu Kunihiro Sato 《Optical Review》2007,14(4):246-251
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. 相似文献
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Conventional all-optical switches based on azo polymer films and the all-optical switches based on the attenuated total reflection (ATR) geometry are investigated. A conventional switch system, including a pump beam of 532 nm and a probe beam of 650 nm, is based on the photoinduced birefringence effect of azo polymer. An ATR switch in a prism-multilayer configuration is achieved by changing the reflectance of the probe beam with an external pump beam. The ATR method provides the substantial improvement of the speed and the efficiency of the modulation over the conventional method. Although the azo polymer response still remains relatively slow, an enhanced nonlinear refractive index of the azo polymer film can effectively increase the modulation. 相似文献
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It is shown that bright-dark Manakov solitons can be formed in biased guest-host photorefractive polymer when the total intensity of two components is much lower than the background illumination.The existing conditions of bright-dark Manakov solitons are discussed in detail.The intensity profiles and dynamical evolutions of solitons are presented by numerical methods. 相似文献
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不同生色团对聚合物薄膜全光开关效应的影响 总被引:3,自引:3,他引:3
在聚甲基丙烯酸甲酯(PMMA)中掺人不同的偶氮染料并制成薄膜样品,以调制的线偏振Ar^ 激光(514nrn,CW)作为控制光,He-Ne激光(632.8nm,CW)为信号光,研究了样品的光致双折射效应及全光开关效应。通过对样品的响应特性和全光开关效应进行比较,发现电子推拉势较强的生色团分子在控制光作用下,可以产生较大的光致双折射效应,但光响应速度较慢,其光致双折射效应以光致异构取向为主要机制;而对于具有较弱电子推拉势的生色团分子,其光致双折射效应则主要来自光致异构烧孔机制,虽然其光致双折射效应小,但光响应速度快。 相似文献
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In the biased guest-host photorefractive polymer,the Manakov equations can be used to describe the optical soliton propagation and interaction.Hereby for such equations,via the Hirota method and symbolic computation,analytic soliton solutions in the bright-dark and dark-dark forms are obtained.Based on the choice of photorefractive polymer parameter and incident-optical-beam parameter,the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination,and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation.γ,representing the soliton intensity far away from the soliton center,determines the appearance of bright or dark soliton under the background illumination.Through the graphic and asymptotic analysis on the two-soliton solutions along with the different γ,we find that there exist the elastic and inelastic interactions between the bright-dark solitons,while the interactions between the dark-dark solitons are always elastic. 相似文献
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In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the optical soliton propagation and interaction. Hereby for such equations, via the Hirota method and symbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefractive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. γ, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different γ, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic. 相似文献
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Photoinduced Birefringence and Broadband All-Optical Photonic Switch in a Bacteriorhodopsin/Polymer Composite Film 下载免费PDF全文
Photoinduced birefringence with large optical nonlinearity in a bacteriorhodopsin/polymer composite film is observed. A high refractive index change of 8.5×10-5 photoinduced by 476nm pumping beam is reached at the low intensity of 6.5mW/cm2. Based on it, a broadband all-optical photonicswitch is realized with an optical controlling switch system. Because of controlling beam's selectivity in switching, the transporting beams of different wavelengths with different intensities and shapes can be modulated by adjusting the wavelength and intensity of the controlling beam. 相似文献
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光折变介质中空间光孤子自弯曲现象研究 总被引:1,自引:0,他引:1
光折变非线性介质在外加直流电压时会引起介质内部电荷移动,而移动后的电荷又会导致空间电荷的扩散效应,从而产生非局域非线性现象。从理论上研究了具有流动和扩散非局域非线性的光折变晶体中所支持的空间光学孤子的传播行为。应用等效粒子近似方法分析了这类介质中(1 1)维空间光学孤子动力学行为,得出孤子运动"加速度"显式解。孤子的有效"加速度"决定于孤子参量和光折变非局域参量。所得的解析结果可在一定参量范围内直接用来计算孤子的传播轨迹。对孤子在光折变非局域非线性作用下的传播动力学行为做了仿真模拟,数值模拟结果与理论分析结论符合得很好。 相似文献
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用重复旋转涂膜法制备了乙基红(ER)偶氮染料与聚甲基丙烯酸甲酯(PMMA)掺杂聚合物薄膜和乙基橙(EO)与聚乙烯醇(PVA)掺杂聚合物薄膜.测量了两种聚合物薄膜样品全光开关特性,比较分析了薄膜样品的掺杂浓度和溶剂对全光开关效应的影响,实验结果表明:增加掺杂浓度和溶剂,极性薄膜样品的全光开关效应增强且开关的本底信号增大,但对开关的响应速度影响很小;选择合适的掺杂浓度和强极性溶剂,在室温和几个mW的弱功率控制光条件下聚合物薄膜具有毫秒级开关响应时间和40%以上的开关调制深度,最大的调制深度达72%以上. 相似文献
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研究和开发基于超短波和低能量激光系统的高振幅、宽频带的太赫兹系统一直是太赫兹应用领域的一个热点。与传统电光晶体材料相比,以电光聚合物薄膜作为太赫兹波产生和检测的最大的优势在于: 一方面电光聚合物不具有晶格结构相应的不存在声子的吸收和太赫兹折射率的散射问题,避免光谱间隙的产生;另一方面电光聚合物薄膜与已用于宽频太赫兹系统中的超薄电光晶体材料相比,更易于加工和处理。另外,可以自行设计得到低相位失配和高电光系数的电光聚合物材料,得到高效率和宽频带的太赫兹辐射源。可以预见,电光聚合物在这一领域的应用必将有宽阔的发展空间和学术研究意义。介绍电光聚合物的电光效应及二阶非线性生色团合成等相关理论问题基础上,综述了近二十多年来,电光聚合物在基于全光技术实现太赫兹波产生与检测系统中的研究进展,主要包括: 掺钛蓝宝石飞秒激光激发下,共聚型和主客体型电光聚合物实现太赫兹波产生与检测;光纤飞秒激光激发下,主客体型电光聚合物实现太赫兹波的产生与检测。 相似文献
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光折变两波耦合对光扇开效应的抑制作用 总被引:4,自引:0,他引:4
以多个两波耦合(TWM)相位栅模型建立了考虑光扇开效应后的动态两波耦合方程,通过数值求解揭示了在大信号两波耦合对光扇开效应的抑制作用和在小信号下光束扇开损耗对两波耦合影响的规律,并进行了相应的实验研究。 相似文献