共查询到17条相似文献,搜索用时 703 毫秒
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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:6,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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于晓光 《中国光学与应用光学文摘》2006,(1)
O4372006010275不同基体刚性偶氮化合物光致光学各向异性及其唯象模拟=Photoinduced anisotropy of azo polymer with differentmatrices rigidity and their phenomenological si mulation[刊,中]/罗锻斌(华东理工大学物理系.上海(200237)),邓莉∥光学学报.—2005,25(10).—1385-1390在不同刚性的聚合物基体聚甲基丙烯酸甲酯(PM-MA)、聚乙烯咔唑(PVK)和聚苯乙烯(PS)薄膜基体中掺入相同质量分数(均为0.003)的分散红13(DR13)偶氮染料。以线偏振连续Ar 激光(514nm)作为控制光,连续He-Ne激光(632.8nm)作为信号光,考察了具有相同厚度的3… 相似文献
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在不同温度下,分别测量了掺杂偶氮材料、偶氮聚合物和偶氮液晶聚合物的光致双折射行为,并利用双e指数模型对光致双折射的动力学过程进行了拟合.实验结果表明,偶氮材料的光致双折射源于偶氮分子的光致异构和光致分子取向,光致双折射大小随温度的升高表现出先增大后减小的趋势.在抽运光的作用下,含偶氮材料的光致双折射包含一个由偶氮分子取向引起的快过程和一个由偶氮分子带动大分子取向引起的慢过程.关闭抽运光后,掺杂偶氮材料和偶氮聚合物表现为可逆的弛豫,而偶氮液晶聚合物则展现出长久光存储特性. 相似文献
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报道了通过宏观测量偶氮聚合物光致异构效应,及其引起的光学各向异性变化,讨论了一种影响偶氮聚合物顺反异构效应的有效途径。在偶氮高分子聚合物中,添加了不同浓度的Ag纳米粒子,采用了波长为442nm的He-Cd偏振激光为激发光源,当Ag纳米粒子掺杂质量浓度为0.12μg/ml的时候,激发了薄膜样品中Ag纳米粒子的等离子体共振效应,增强了粒子周围纳米尺度的电磁场强度,相当程度上提高了偶氮聚合物光致异构的转换效率;另外,研究了不同的取代基同纳米Ag粒子的相互作用对光致异构效应的影响,探讨了一种能够有效地控制光致异构效应的方法。 相似文献
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新型偶氮苯侧链共聚物的超快光致双折射特性 总被引:9,自引:5,他引:4
采用抽运探测方法测量了一种新型的含 4 偶氮苯 4′ 偶氮苯酚侧链的共聚物 (DAP PGMA)的光致异构特性。实验结果表明DAP PGMA比含单偶氮苯侧链共聚物P (MMA co MAZ)有较大的光致双折射效应 ,Δn~ 6 .6 0× 10 -4 ;同时DAP PGMA比P(MMA co MAZ)具有更快的开启速度 ,光致向向异性上升时间为 40 ps,这种皮秒量级的快过程对应于双偶氮苯生色团的顺反异构过程。 相似文献
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研究一种新型的并列式的高密度存储材料ADPA-PVK-PBA-TNF聚合物薄膜.在非吸收区用光抽运测试法研究了薄膜光致双折射,获得光致双折射变化值Δn=1.3×10-3,分析了该聚合物薄膜光致取向增强的物理和化学机理.探讨了抽运光对光致双折射的增强和抑制效应.在此基础上初步实现了多重角度复用信息存储、获得了较为清晰的全息存储图像.并讨论了图象存储的增强/抑制效应,利用这种效应可对存储图像处理或删除.
关键词:
掺杂偶氮苯聚合物薄膜
光致双折射
光全息存储
光致取向增强 相似文献
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Bassam Abbas Yousef T. Salman Moustafa S. El-Daher 《Journal of Macromolecular Science: Physics》2015,54(12):1457-1465
Photoinduced birefringence in poly(methyl methacrylate) (PMMA), polymeric thin films doped with di-azo Sudan G was investigated. A pump-probe method was used to study the dynamic behavior of the birefringence. The mechanism for the inducement of birefringence is discussed in terms of the photoisomerization of the di-azo Sudan G molecules. The results showed that the dynamic evolution of the photoinduced birefringence was such that the average birefringence increased, saturated, and then decreased with respect to the laser pump intensity. Also, an exponential-like relationship was observed between both the saturation and the isotropic states of the averaged transmitted probe beam (expressing the residual anisotropy) and the birefringence on one hand, and the intensity amplitudes of the pumping powers on the other hand. 相似文献
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Sheng-fa Fan 《Optik》2011,122(2):142-144
The optical anisotropic states in the azo-dye Disperse Red 13 doped poly(methyl methacrylate) polymeric film are induced by polarized light and the nonlinear refractive index in these states are studied by the Z-scan technique. It is found that the n2 of the sample can be controlled by changing both the polarization direction and the intensity of the 514 nm light. Photo-induced isomerization and reorientation of azo chromophores in polymer matrices are used to explain the results. 相似文献
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建立了光致变色二芳基乙烯样品光致各向异性动力学的理论模型.计算了在线偏振光激发下,二芳基乙烯分子数密度、光致二向色性和光致双折射随时间(曝光量)的动态变化曲线.结果表明,随着激发曝光量的增加,二芳基乙烯呈色态分子数密度不断下降直至饱和,光致各向异性随曝光量增加先增加,达到最大之后开始下降,最佳曝光量为260J/cm2.利用正交偏振检测方法测量了反映材料各向异性的探测光透过率动力学曲线,并与理论计算结果进行了比较,二者基本相符.
关键词:
光致各向异性
二芳基乙烯
动态特性
最佳曝光量 相似文献
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Hye Ri Yang 《Optics Communications》2009,282(9):1902-262
We fabricated azo dye (methylorange) doped poly vinyl alcohol (MO/PVA) thin films and measured the photoinduced birefringence (PIB) kinetics for several pump beam intensities and for various MO concentrations by using the pump-probe technique. A novel approach to explain the transient behaviors of the photoinduced anisotropy is presented by employing an empirical stretched exponential time response in the course of the trans-cis-trans photoisomerization of azo molecules and is compared with the experimental data, showing excellent agreement. The stretched exponent is estimated to be β = 0.34 ± 0.04, revealing amorphous nature of the MO/PVA system. 相似文献
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Yanhua Luo Zengchang Li Ru Chen Qijin Zhang Gangding Peng Gang Zou Bing Zhu 《Optics Communications》2009,282(12):2348-2353
Based on the photoinduced birefringence in azo materials, the model of the birefringent long period fiber gratings (BLPFGs) has been proposed and the transmission of such birefringent fiber gratings was further simulated by the coupled mode theory. In order to obtain the optimum condition for making birefringent azopolymer optical fiber (APOF) gratings the photoinduced birefringence of azo dye and methyl methacrylate (MMA) copolymers was systematically studied. After photosensitivity study of azo samples, using Teflon technique, azo dye containing single mode polymer optical fiber (POF) was fabricated. Finally, BLPFGs can be fabricated in azopolymer fiber using polarized 532 nm laser. A 120 μm LPFG with a 50% duty cycle has been successfully written within the core of the fiber with 532 nm laser by an amplitude mask method. Under polarized microphotography, the grating was observed when the optical axis was set at 45° with the direction of the first polarizing lens of the polarization microscope. 相似文献
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M. Ivanov L. Nikolova T. Todorov N. Tomova V. Dragostinova 《Optical and Quantum Electronics》1994,26(11):1013-1018
Photoinduced anisotropy in films of azo-dye Mordant Pure Yellow (MPY) dissolved in a polyvinyl alcohol matrix, is investigated. The photodichroism and photoinduced birefringence are measured in real time for two wavelengths, 488 nm (in the absorption band) and 633 nm (outside it), on excitation with an Ar+ laser beam. It is shown that strong dichroism is induced without changing the average optical density of the film, and the kinetic curves of the birefringence and the dichroism are substantially different. The conclusion is made that the photoprocesses of the dye molecules cause a reconstruction of the matrix. 相似文献