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1.
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   

2.
偶氮苯聚合物薄膜光致微结构的研究   总被引:1,自引:1,他引:1  
利用光场梯度力理论,对前向四波混频光路制作偶氮苯聚合物薄膜表面微结构的结果进行解释,经过分析认为用这种方法制作亚微米微结构存在机理缺陷.采用“Step-by-Step”制作偶氮苯聚合物薄膜表面四方微结构,该方法将是制作二维亚微米微结构的有效手段,同时指出这种规则微结构光学各向异性特点有利于二维光子晶体完全带隙的形成.  相似文献   

3.
偶氮苯聚合物薄膜光致六角对称微结构   总被引:2,自引:2,他引:0  
利用前向箭并四波混频光路,在偶氮苯聚合物薄膜表面制作出六角对称的晶体微结构,观察到多个相位共轭波,当三束入射光都处在p偏振态时,在样品表面可得到一维光栅,当三束入射光中有一束在p偏振态,另两束在s偏振态时,在样品表面上得到的是六角对称微结构,这一结果表明,光场强度周期性变化及光场偏振态对晶格微结构的形成非常重要。  相似文献   

4.
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   

5.
合成了带有不同取代基的偶氮苯基团和可交联丙烯酸基团的共聚物,并通过控制热聚合的反应条件获得一系列不同交联密度的聚合物薄膜. 红外光谱表征样品交联度是从0到32%. 不同交联密度的偶氮聚合物薄膜的光致取向行为的研究结果表明交联能够降低光致取向速率以及薄膜的最大透过率. 进一步的重复擦写实验还表明交联薄膜能够有效抑制在线偏光擦写过程中偶氮苯分子的趋光性质量迁移.  相似文献   

6.
谢茹胜  赵有源 《物理学报》2011,60(5):54202-054202
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   

7.
王长顺  尹国盛 《光子学报》1998,27(10):906-910
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   

8.
光致异构全光逻辑门理论与实验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
李燕明  陈理想  佘卫龙 《物理学报》2007,56(10):5895-5902
基于双光抽运探测模型,利用偶氮苯聚合物光致异构和光致双折射效应,建立了全光逻辑门的理论分析模型,提出了一种新颖的全光逻辑门设计方案.该方案基于输入抽运光和信号光的强度或偏振态,设计了“与”门、“或”门、“异或”门和“异或非”门等基本功能的全光逻辑门.以掺杂分散红1(DR1)的聚甲基丙烯酸甲酯(PMMA)薄膜为样品进行实验,得到了比较好的逻辑门运算实验结果,与理论分析相符合.  相似文献   

9.
偶氮液晶聚合物中的非线性光致双折射   总被引:1,自引:0,他引:1       下载免费PDF全文
介绍了在偶氮液晶聚合物薄膜P-CN中发现的非线性光致双折射现象,给出了非线性光致双折射实验的具体结果.采用Z扫描技术验证了光致双折射的非线性过程本质,测量了P-CN介质薄膜的非线性吸收系数.讨论了光致双折射涉及的异构化微观机理,并在此基础上提出了非线性光光异构化实现光致双折射的方法 关键词: 液晶聚合物 光致双折射 光致异构化  相似文献   

10.
吕子瑶  潘雨佳  王长顺 《物理学报》2017,66(24):244203-244203
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   

11.
借助于表面增强共振拉曼光谱散射(SERRS)技术, 研究了一种新型的偶氮聚合物材料侧链含咔唑与偶氮分散红共聚物(CAP)在化学沉积法制备的银膜表面的拉曼峰增强和吸附行为. 实验结果显示, CAP在银表面的状态为: 聚合物通过咔唑单体中咔唑基团和偶氮单体中硝基与银膜衬底发生物理吸附, 而聚合物的主链与衬底相距较远没有相互作用. 可以推测, 聚合物在衬底表面的这种状态将对偶氮光存储器件的稳定性和工作效率产生不良影响.  相似文献   

12.
We have observed reversible light-induced mechanical switching for individual organic molecules bound to a metal surface. Scanning tunneling microscopy (STM) was used to image the features of individual azobenzene molecules on Au(111) before and after reversibly cycling their mechanical structure between trans and cis states using light. Azobenzene molecules were engineered to increase their surface photomechanical activity by attaching varying numbers of tert-butyl (TB) ligands ("legs") to the azobenzene phenyl rings. STM images show that increasing the number of TB legs "lifts" the azobenzene molecules from the substrate, thereby increasing molecular photomechanical activity by decreasing molecule-surface coupling.  相似文献   

13.
李梦梦  朱宝华  冉霞  刘波  郭立俊 《物理学报》2016,65(2):24207-024207
本文以30 ps的脉冲激光为激发光源,用Z扫描技术研究了偶氮苯类材料4-羟基-4’-羧基偶氮苯(BN)和N-(3,4,5-辛氧基苯基)-N’-4-[(4-羟基苯)偶氮苯]1,3,4-恶二唑(AOB-t8)及金属复合物(Au/AOB-t8)的三阶非线性光学性质,并从理论上进行了分析和计算.结果表明,AOB-t8的三阶非线性极化率是BN的1.38倍,其非线性光学效应的增大是由共轭链增长、大π键增多引起的.结果同时给出,AOB-t8的三阶非线性极化率是其与金纳米颗粒复合物的4.7倍,这种与金属复合产生的非线性光学效应的减弱是金属引入的局域场效应与有机分子大π键作用之间相互抵消导致的.  相似文献   

14.
We propose techniques of hologram replication in glass plates and reconstruction on another film by corona charging. A surface relief hologram on an azobenzene polymer film was recorded in the form of electric polarization in glass plates that include alkali cations by corona charging at high temperature. The hologram recorded in the glass plate is stable for more than 1 month at room temperature. After removal of the azobenzene polymer film from the plate, poly(methyl methacrylate) (PMMA) film was spin-coated onto the plate. The hologram recorded in the plate was reconstructed with the same surface relief structure on the PMMA film by corona charging again at 110°C.  相似文献   

15.
Light-induced surface modification of a series of liquid-crystalline side-chain azobenzene polyesters which have the same main- and side-chain structure but eleven different substituents on the azobenzene is investigated. Using a transmission mask as well as single focused beams we show that the formation of the surface relief is dependent on the substituents. In both experiments irradiation with p-polarized light generates peaks for the CN, CF3, CH3 and F substituents, while for a Cl substituent valleys are observed. Also s-polarized light is found to produce surface deformations. An amorphous azobenzene polyester was included in the study for comparison. The results point to a mechanism of the surface relief phenomenon, in which the architecture of the polyesters plays a crucial role. Received: 11 September 2000 / Revised version: 4 December 2000 / Published online: 21 February 2001  相似文献   

16.
We propose a method of hologram recording in a glass plate by corona charging. The holographic recording materials used in this study are conventional soda-lime glass and azobenzene polymer film. A Fourier transform hologram on an azobenzene polymer film coated on the glass plate is recorded in the glass plate by corona charging. After removing the polymer film, the hologram recorded in the plate can be reconstructed using a visible-wavelength laser beam. The first-order diffraction efficiency of the hologram at a wavelength of 532 nm is 0.03%; the efficiency depends on the depth of the surface relief structure on the azobenzene polymer film and the corona-charging time. The hologram recorded in the glass plate has high environmental resistance.  相似文献   

17.
《中国物理 B》2021,30(9):96805-096805
The orientation switching of a single azobenzene molecule on Au(111) surface excited by tunneling electrons and/or photons has been demonstrated in recent experiments. Here we investigate the rotation behavior of this molecular rotor by first-principles density functional theory(DFT) calculation. The anchor phenyl ring prefers adsorption on top of the fcc hollow site, simulated by a benzene molecule on close packed atomic surface. The adsorption energy for an azobenzene molecule on Au(111) surface is calculated to be about 1.76 e V. The rotational energy profile has been mapped with one of the phenyl rings pivots around the fcc hollow site, illustrating a potential barrier about 50 me V. The results are consistent with experimental observations and valuable for exploring a broad spectrum of molecules on this noble metal surface.  相似文献   

18.
Three different molecules, each containing two azobenzene switching units, were synthesized, successfully deposited onto a Au(111) surface by sublimation and studied by scanning tunneling microscopy at low temperatures. To investigate the influence of electronic coupling between the switching units as well as to the surface, the two azo moieties were connected either via π-conjugated para-phenylene or decoupling meta-phenylene bridges, and the number of tert-butyl groups was varied in the meta-phenylene-linked derivatives. Single molecules were found to be intact after deposition as identified by their characteristic appearance in STM images. Due to their mobility on the Au(111) surface at room temperature, the molecules spontaneously formed self-organized molecular arrangements that reflected their chemical structure. While lateral displacement of the molecules was accomplished by manipulation, trans-cis isomerization processes, typical for azobenzene switches, could not be induced.  相似文献   

19.
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   

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