共查询到18条相似文献,搜索用时 109 毫秒
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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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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 总被引:1,自引:0,他引:1
在不同刚性的聚合物基体聚甲基丙烯酸甲酯(PMMA)、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(DRl3)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三种样品在相同控制光功率(15mW)下的光致双折射效应。实验发现刚性较大的聚乙烯咔唑基体样品的双折射效应最小,刚性最小的聚苯乙烯基体样品的双折射效应最大。在偶氮生色团光致异构的四能级模型基础上,建立一新的唯象的模型。在模型中引入描述聚合物基体刚性的参量s,通过数值计算描述了不同基体刚性参量s对偶氮生色团光致异构取向的影响。计算结果表明,基体的刚性越大,样品的光致双折射效应越小,定性地解释了实验现象。 相似文献
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在吲哚俘精酰胺/PMMA薄膜上记录了同偏振全息和正交偏振全息图,获得了它们的再现衍射像.实验结果表明:吲哚俘精酰胺具有光致各向异性,可以进行正交偏振全息记录.在偏振全息中,衍射光的偏振方向依赖于物光和再现光的偏振方向,衍射像的噪声主要来源于再现光照射到样品上引起的散射.正交偏振全息可以得到比同偏振全息更高信噪比的衍射像.存储于样品上的全息图在室温下黑暗处至少可以保存五个月而衍射效率无明显下降.结果表明,吲哚俘精酰胺是一种可用于偏振全息的可擦重写记录介质.
关键词:
偏振全息
光致各向异性
俘精酸酐
光致变色 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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设计了一种基于菌紫质光致各向异性的相移器,并把它用于相移干涉计量。取向随机分布的极性菌紫质分子对线偏振诱导光的选择性吸收导致分子取向分布不均匀,使其呈现宏观的各向异性,这种各向异性与诱导光的偏振特性密切相关,圆偏振光经过各向异性的菌紫质薄膜后,出射光的偏振特性完全由偏振诱导光决定。基于上述原理设计了一种新型的相移器,用琼斯矩阵法推导了基于相移器的相移干涉原理。该相移器在工作过程中不需要移动Mach-Zender干涉仪内部的任何器件,仅需要改变外部控制光路中诱导光的偏振取向就可以控制参考光的相位,有助于提高设备的抗振能力。用最小二乘法对相移干涉结果进行重建,得到了和实际相位一致的结果,验证了相移器的可行性。 相似文献
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在聚合物表面刻写方格子的新方法及理论研究 总被引:1,自引:0,他引:1
为了提高制作偶氮苯微结构的实验技术,在偶氮苯聚合物的光致异构和光致取向特性的基础上,利用两激光束的新实验方案,运用比较简便的分步制作的方法,成功的在偶氮苯功能化聚合物薄膜表面“刻写”出二维的正方格子结构。提出了一个新的光异构取向场理论:在两束偏振方向互相垂直的偏振光照射下,偶氮苯聚合物表面光栅的形成是光异构取向场的干涉的结果,并对实验现象进行了解释。用计算机对实验结果进行了模拟,将模拟结果与实验结果进行了比较,结果表明计算机模拟将会更加有利于偶氮苯聚合物微结构的设计和制作。 相似文献
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Polarization holographic recording was investigated in a liquid-crystalline azobenzene side-chain polymer. A highly stable
polarization holographic grating with the diffraction efficiency of 12.6% was written in the polymer film by two orthogonally
linearly polarized 532 nm beams with equal intensities of 150 mW/cm2. The polarization grating was studied with a 633 nm probe beam by surveying the conversion of the polarization state of the
probe beam and measuring the dependence of diffraction efficiency on the polarization direction of the probe beam. It was
found that the ± first-order diffraction efficiency and the polarization of the diffracted wave depended strongly on the polarization
of the readout wave. The unusual diffraction properties of the recorded grating were attributed to the presence of the circular
photoinduced birefringence.
PACS 42.40.Ht; 42.40.Lx; 78.20.Fm 相似文献
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In this paper we demonstrated enhancement of photoinduced polarization rotation for improved transmission of laser light at low input intensities through a crossed polarized system. It is achieved by utilizing two azobenzene doped polymer thin films in tandem. As the input beam propagates through the films, its polarization rotation induced by each film is additive. We obtained polarization rotation of as much as 24° resulting in enhanced transmission compared to a single-film approach. In addition, this novel design is promising for use as a broadband nonlinear transmission system. 相似文献
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Simultaneous writing and probing of photoinduced second-order susceptibility chi((2)) in an azo-dye polymer thin film is demonstrated. The method is based on the fact that tensor properties of chi((2)) provide different planes of polarization for seeding and signal second harmonics. Our technique allows the chi((2)) value to be monitored in real time, completely eliminating the distortion of optical poling that can occur in traditional probing configurations. The possibility of attaining high values of chi((2)) in a DR1-PMMA guest?host system under low seeding intensities is shown. 相似文献
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Fuli Zhao Jun Wu Zhihua Pan Changshun Wang Jinwen Zhang Yi Zeng Xuemin Lu 《Optics Communications》2012,285(21-22):4180-4183
Photoinduced anisotropy and polarization holographic recording were investigated in an azobenzene-containing ionic self-assembly complex. The complex film was found to possess large photoinduced dichroism (D~0.36) and photoinduced birefringence (Δn~10?2). A noteworthy observation was that the photoinduced birefringence did not show any decay, but strongly increased after switching off the pump light at room temperature. The diffracted signals of the polarization holographic gratings, written by two orthogonally linear and circular polarized beams respectively, exhibited similar inverse relaxation behavior as the photoinduced birefringence after switching off the writing lights. A discussion about the mechanism accounting for the abnormal relaxation process of photoinduced birefringence is presented. 相似文献
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We use two parallel nano-slits in a silver film to form a surface plasmon Mach Zehnder interferometer (MZI), based on the interference of two surface plasmon waves propagating along the two surfaces of the silver film. Coating the silver film with a photoinduced birefringence polymer film, we achieve optical modulation of the MZI output by changing the refractive index of the polymer film with a pump beam. An on/off ratio 0f 2. 7 is obtained for a probe wavelength of 865 nm. 相似文献
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It is shown that photoinduced dichroism in photosensitive AgCl films with Ag granules can be used to record the spectral dependence of the state of polarization specified by anisotropic crystals. The recording of the state of polarization throughout the visible spectral region is favored by the frequency photoadaptation, which is typical of AgCl–Ag films. This effect also determines the good reproduction of color corresponding to the spectrum of the irradiating beam. The results show the feasibility of determining the magnitude of photoinduced dichroism and its dispersion by analyzing the pattern recorded in a film in polarized light. 相似文献