共查询到18条相似文献,搜索用时 62 毫秒
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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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将偶氮化合物乙基橙样品置于一对正交的偏振片之间,用一束激发光照射该样品,分别测量 在激发光的不同强度和不同偏振方向下探测光的透射功率,研究样品的双折射特性.实验表 明,透射光的饱和值和稳定值与激发光强成正比,且与激发光偏振方向有关,探测光与激发 光振动方向的夹角(θ)为45°时,其值最大;若θ不太小(>10°),sin22θ 与透射光的饱和值、稳定值成线性关系.同时,利用巴俾涅补偿器对样品的双折射率差进 行了测量,分别得到了绿光激发前后的准确数值为1.11×10-3和3.57×10 -3.
关键词:
偶氮
双折射
测量 相似文献
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偶氮苯侧链聚合物液晶薄膜的光致双折射和永久光学性存储研究 总被引:9,自引:8,他引:1
研究了一种含偶氮基侧链聚合物液晶薄膜,该液晶薄膜表现出显着的光致双折射(Δn~1.1×10-2).当关闭写光作用后,光致双折射的大小没有任何衰减,表现出永久光存储特性.光致双折射的擦除可通过将样品加热到接近其清亮点温度,或用一束圆偏振光照射来实现.分析了偶氮侧链聚合物永久性光学存储的物理机制. 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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利用偏振全息记录的方法在一种含偶氮侧链的液晶聚合物薄膜中写入了二维偏振光栅.实验采用两束正交偏振的532 nm线偏光作为写入光,在样品同一点上分别记录了相互垂直的两个一维偏振光栅,继而对所构成的二维偏振光栅的特性进行了研究.实验结果表明:二维光栅的衍射效率比一维光栅低,其偏振特性是两个一维光栅元特性的叠加;二维光栅衍射效率对入射光偏振态的依赖性和光栅的偏振转换性质来源于材料中线双折射和圆双折射的共同作用.
关键词:
偏振全息
二维光栅
偶氮液晶聚合物 相似文献
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The nonlinear refraction and photoinduced birefringence of chlorophosphonazo I (CPA I ) doped PVA thin films were investigated. The single-beam Z-scan measurement showed that CPA I doped PVA thin film possessed a large value of nonlinear refractive index (n2=1.82×10−12 cm2/W) under a pulse 532 nm excitation, and the mechanism accounting for the process of nonlinear refraction was discussed in term of resonant electronic effect. Moreover, fast and stable molecular reorientation was observed when investigating the photoinduced birefringence of CPA I doped PVA thin film with a CW 532 nm laser as pump light and a CW 650 nm laser as probe light. 相似文献
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偶氮聚合物薄膜的全光极化研究 总被引:4,自引:0,他引:4
报告了分散红共聚物膜HMMM-DR1,HMMM-DR19和偶氮侧链聚合物膜PCN6和PCN2的合成和制备, 并以HMMM-DR1和PCN6为代表比较研究了这两种具有不同吸收性质材料的全光极化特性,研究了他们的实时极化和弛豫过程,对他们的全光极化性质作了最基本的表征.研究了倍频光吸收对薄膜光极化效率的影响,讨论了偶氮聚合物材料光诱导二阶非线性极化率的效率和倍频光透射率之间的折衷关系,这对实用化的全光器件的研制是至关重要的.实验确证了在PCN6薄膜中实现了准相位匹配.对厚膜中光诱导二阶非线性极化率的弛豫抑制效应作出解释. 相似文献
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The nonlinear optical properties of an azobenzene polymer azol2-MO were investigated by a Z-scan technique. The polymer was synthesized by assembling the liquid-crystalline polymer azol2 with methyl orange. The nonlinear refrac- tive index (1.39×10^-15 cm2/W) and the nonlinear absorption coefficient (0.11 cm/GW) of azol2-MO were determined with 532-nm picosecond laser pulses at the irradiance of 92.40 GW/cm2. When compared to the nonlinear properties of azol2 and methyl orange, azol2-MO possesses the advantages of its two constituents and shows larger nonlinear optical properties. 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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G. A. Puchkovskaya A. G. Tereshchenko L. I. Shanskii O. V. Yaroshchuk 《Journal of Applied Spectroscopy》1998,65(1):124-129
The process of optical anisotropy indiction in azopolymer films upon irradiation by polarized UV light is studied by means
of UV and IR birefringence spectroscopy. A substantial dependence of the character of the relaxation of the induced anisotropy
on the exposure time to the exciting light is revealed: whereas the process of anisotropy induction is reversible at small
exposure times, at large exposure times the induced anisotropy virtually does not relax and even increases after the irradiation
is terminated. A difference between kinetic curves of dichroism and birefringence induction is shown: at exposure times corresponding
to the saturation of the induced dichroism a slow increase in the birefringence curve is observed. Results obtained are explained
in terms of the assumption of partial ordering of macrochain fragments in irradiated films. The assumption is substantiated
by measurements of polarized IR spectra.
Institute of Physics of the National Academy of Sciences of Ukraine, 46, Nauka Ave., Kiev, 252650, Ukraine. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 121–125, January–February, 1998. 相似文献
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Gilbert Y Bachelot R Royer P Bouhelier A Wiederrecht GP Novotny L 《Optics letters》2006,31(5):613-615
The effects of tightly focused, higher-order laser beams on the photoinduced molecular migration and surface deformations in azobenzene polymer films are investigated. We demonstrate that the surface relief is principally triggered by longitudinal fields, i.e., electric fields polarized along the optical axis of the focused beam. Our findings can be explained by the translational diffusion of isomerized chromophores when the constraining effect of the polymer-air interface is considered. 相似文献