Poly－3BCMU薄膜光漂白的实验研究

报道了Ｐｏｌｙ－３ＢＣＭＵ薄膜光漂白过程的实验研究结果。测量了薄膜光漂白前后的可见及紫外光谱的变化，表明在光漂白过程中聚合物的长链被逐渐打断。实验表明，被漂白的聚合物薄膜可以被某些有机溶剂溶解，导致所谓的显影过程。实验研究了氧对光漂白过程的影响，并发现在Ｐｏｌｙ－３ＢＣＭＵ薄膜表面涂复光刻胶薄层可阻止氧分子向薄膜内的扩散，从而大大减缓光漂白过程。本文同时对光漂白在制备光波导元件中的应用进行了研究。     

Poly-3BCMU 薄膜光漂白过程的理论模型

本文报道了使用两种不同漂白光源时,Poly-3BCMU薄膜的光漂白过程,并建立了描述漂白过程的理论模型.最后讨论了采用光漂白方法制备导波微光学元件的可能性.     

Poly—3BCMU薄膜光漂白的实验研究

报道了Ｐｏｌｙ－３ＢＣＭＵ薄膜光漂白过程的实验研究结果。测量了薄膜漂白前后的可见及紫外光谱的变化，表明在光漂白过程中聚合物的长链被逐断打断。实验表明，被漂白的聚合物薄膜可以被某些有机溶剂溶解，导致所谓的显影响过程。     

利用分子梳方法研究单个DNA-YOYO-1复合体的光漂白性质

利用分子梳方法结合荧光显微术对单个DNA-YOYO-1复合体的光漂白过程进行了研究,发现单个DNA-YOYO-1复合体的光漂白是一个随光照时间指数衰减的过程,并给出了DNA拓扑结构以及光照强度对光漂白过程的影响.     

激光单分子探测的实验研究

单分子探测技术是一项超高灵敏度的探测技术，在生物、医学和环境等领域有着广泛的应用。在这里，本文简要介绍了基于激光诱发荧光方法的单分子探测谱仪的原理和装置，以及用ＣＣ５染料分子在该探测谱仪上进行的若干实验研究结果，包括样品流速的影响、能量特性、浓度线性、检测限等方面，并讨论了光漂白现象对实验结果的影响。     

厦门湾有色溶解有机物光漂白的三维荧光光谱研究

利用荧光激发-发射矩阵光谱(excitation-emission matrix spectroscopy,EEMs)研究了厦门湾九龙江河口中、低盐度区表层水样中有色溶解有机物在秋季天然太阳辐照下的光化学漂白。结果表明,光漂白未引起水样中类腐殖质(C, A, M)和类蛋白质(T,B)荧光峰位置的移动。5个峰的荧光强度均随辐照时间的增加而减少,其中低盐度水样的降低幅度更大,并以指示陆源河流输入的特征荧光峰C的光漂白程度最大。根据漂白速率可将各荧光团区分出易漂白和难漂白两类组分。光漂白导致T、C峰及A、C峰之间的荧光强度比值增加,说明光漂白可引起海水中溶解有机物性质的明显改变,并且也是近海类蛋白质荧光相对类腐殖质荧光占优势的一个重要控制因素。研究结果对于探究陆源有机物在近海的转化及去除过程以及海洋光学有一定的参考价值。     

生物相容性量子点的表征及其在细胞标记中的应用

利用无机低温水相合成法制备表面包覆L-半胱氨酸的CdTe/ZnTe核壳型量子点,测量不同溶液以及激发功率激光作用下该量子点的光谱特性。结果表明,该量子点吸收谱和荧光光谱峰值位置不随pH值变化,而荧光光强随pH值升高呈近似线性上升趋势;不同缓冲液对该量子点荧光光强无影响,但随孵育时间延长,荧光强度略有下降;在强激光照射下QDs会被快速光漂白,选择适当的激光功率(<100 μW),可降低漂白速率,实现长时间稳定测量。因此,该量子点具有较好的生物稳定性和光稳定性,将其与血铁蛋白相连形成靶向共轭纳米粒,可成功用于HeLa细胞标记。细胞内量子点光漂白实验表明,细胞微环境会影响量子点的光稳定性,加速量子点的光漂白。     

聚合物PMMA/DR1啁啾光栅耦合器的研究

从理论上分析出在一定条件下啁啾光栅输出耦合器具有较好的聚焦衍射光束的作用.实验上采用光漂白方法,利用两束激光在PMMA/DR1平面波导上所形成的干涉条纹来制备啁啾光栅,研究了这种啁啾光栅耦合器衍射光的聚焦效应,观测结果与理论分析基本相符.     

肿瘤细胞中表达的GFP蛋白的荧光漂白特性的研究

GFP作为生物源性荧光探针具有其他荧光标记物所无法比拟的优势，目前已广泛应用于生物学研究的各个领域。利用常规转染方法将带有EGFP基因的质粒载体导入人肺腺癌肿瘤细胞(ASTC-a-1)，并得到GFP稳定表达的细胞株。研究中发现，肿瘤细胞中表达的GFP长时间暴露于强激发光中会发生非常强列的荧光漂白作用，并且这种漂白作用是不可恢复的。对不同强度的激发光(饱和光源、阻断片ND4／ND8／ND16)对GFP的漂白作用进行了研究，并对冷冻保存样品的光漂白作用进行了初步的探讨。     

光漂白聚合物波导折射率轮廓的确定

通过实验发现了光漂白聚合物薄膜厚度随光照时间按指数衰减的规律收缩,在此基础上,利用ｍ线法和精确的转移矩阵理论,由数值拟合得到的聚合物波导的折射率轮廓为费米函数。     

Study on the thermo-optic properties of DR1/PMMA composite

This paper reports that the thermo-optic coefficient (\dd n / \dd T) as well as thermal expansion coefficients (\beta) of DR1/PMMA polymer film are measured for both TE (transversal electric) and TM (transversal magnetic) polarizations by using an attenuated total reflection configuration at the wavelengths of 832nm. The thermo-optic coefficients of DR1/PMMA are negative and as high as the order of 10^-4/℃. The influences of dopant concentration, poling process and photobleaching process on the thermo-optic properties of DR1/PMMA are also investigated.     

Dynamics of photoinduced second order nonlinearity in dimethylamino-nitrostilbene polymer thin films

All-optical encoding of macroscopic second order susceptibility in a dimethylamino-nitrostilbene (DANS) polymer thin film is demonstrated. We show that the main mechanism responsible for the induced nonlinearity in DANS polymer is the angular hole burning effect due to trans–cis isomerization as distinct from azo-polymers, in which considerable reorientation of trans-molecules occurs. The DANS sample exhibits better dark stability in comparison with azo-systems such as disperse red 1 polymethylmethacrylate (DR1–PMMA). The results are explained by the absence of thermal cis–trans relaxation in DANS–PMMA.     

Formation of channel optical waveguides in polymethylmethacrylate with embedded electro-optic chromophore DR13 by the photoinduced bleaching method

A composite polymeric material based on polymethylmethacrylate (PMMA) with embedded electro- optical (EO) chromophore DR13 is designed. Irradiation with electromagnetic radiation in the visible range leads to a bleaching of the composite and its refractive index n decreases due to the irreversible photodestruction of the chromophore. Changes in the absorption spectrum and refractive index of the composite with the irradiation time are measured. It is shown that the change in n depends on the concentration of DR13 in the polymer matrix and can reach a value of Δn = 0.034 in the telecommunication C-range near a wavelength of 1.55 μm. The rate of bleaching depends on the wavelength of the actinic light and reaches its maximum when the wavelength is near the maximum of chromophore absorption. With the use of the photobleaching method and the PMMA/DR13 composite, channel waveguides and the other elements of the integrated optical devices are fabricated, including waveguide splitters, directional couplers, and Mach–Zehnder interferometers. This simple one-step method does not involve the removal of polymer material by liquidphase or reactive ion etching.     

纳米ZnO的表面化学修饰及其分析表征

采用水溶性羟丙基甲基纤维素HPMC对无机纳米ZnO粒子进行物理吸附处理 ,获得了核为无机纳米ZnO ,外壳为水溶性高分子HPMC的粒子。然后在其上进行了甲基丙烯酸甲酯的接枝聚合。采用红外光谱、差热分析的方法对复合粒子进行了表征 ,并采用透射电镜观察了粒子的形貌。红外光谱表明在纳米ZnO的表面吸附了HPMC并接枝了PMMA ,差热分析表明HPMC ,HPMC g PMMA和ZnO/HPMC g PMMA的热稳定性逐渐提高 ,透射电镜观察表明 ,在纳米ZnO的表面粘附了一层聚合物 ,成功地实现了纳米粒子的表面修饰。     

聚合物薄膜电光效应研究

介绍聚合物DR/PMMA薄膜材料做成光学法布里-珀罗腔结构,通过观察透射率随外加电场变化,以确定其非线性光学特性参量,在室温和575.0nm时的三阶极化率x~⑶(-ω;ω,0,0)=(5.3-i6.0)×10~((-11)_(θs.u))和二次电光系数R=-(8.5-i9.7)×10~(-19)m~2/V~2.     

PMMA/凝胶玻璃复合材料作为非线性有机分子掺杂基质的研究

对分散红1（DR1）掺杂聚甲基丙烯酸甲酯（PMMA）／凝胶玻璃复合材料的光学二阶非线笥及其热稳定性进行了研究。结果表明,PMMA／凝胶玻璃作为一种有机／无机复合材料,是介于胶玻璃和PMMA之间的一种非线性有机分子掺杂基质。随复合材料中凝胶玻璃含量增多,所制备的非线性材料的热稳定性能变好。对非线性和热稳定性的折衷考虑,获得了制备光学二阶非线笥基质材料先体PMMA和正硅酸乙酯（TEOS）的最佳混合比例。     

Growth of thin polymer films containing side-chain azo-dye analyzed by atomic force microscopy

Thin films containing both the azo-dye disperse red 1 (DR1) and the poly(methylmetacrylate) (PMMA) or the poly(phenylenevinylene) (PPV) are deposited by Langmuir-Blodgett and spin coating techniques on various substrates. The morphology, surface structure and growth pattern of the azo-dye-polymers were studied by atomic force microscopy. Nucleation and growth processes are responsible for the generation of different structures. The spin coated films were additionally oriented using the electric field poling method (corona poling). The film homogeneity is improved by this method in all cases. Due to the polar character of DR1 molecules, rod-like sub-structures are observed after the corona poling process in DR1-MMA films. The indium tin oxide surface enhances reorientation of the azo-dye-polymer molecules during corona poling and results in a significant reduction of the surface roughness.     

Chemically selective soft X‐ray patterning of polymers

The chemically selective modification of polymer mixtures by monochromated soft X‐rays has been explored using the high‐brightness fine‐focused 50 nm beam of a scanning transmission X‐ray microscope. Four different polymer systems were examined: a polymethylmethacrylate (PMMA) polyacrylonitrile (PAN) bilayer film; a PMMA‐blend‐PAN microphase‐separated film; a poly(MMA‐co‐AN) copolymer film; and a poly(ethyl cyanoacrylate) homopolymer film. A high level of chemically selective modification was achieved for the PMMA/PAN bilayer; in particular, irradiation at 288.45 eV selectively removed the carbonyl group from PMMA while irradiation at 286.80 eV selectively reduced the nitrile group of PAN, even when these irradiations were carried out at the same (x,y) position of the sample. In the last two homogenous polymer systems, similar amounts of damage to the nitrile and carbonyl groups occurred during irradiation at either 286.80 or 288.45 eV. This is attributed to damage transfer between the C[triple‐bond]N and C=O groups mediated by primary electrons, secondary electrons or radical/ionic processes, aided by their close spatial proximity. Although the overall thickness of the bilayer sample at 70 nm is smaller than the lateral line spreading of 100 nm, the interface between the layers appears to effectively block the transport of energy, and hence damage, between the two layers. The origins of the line spreading in homogeneous phases and possible origins of the damage blocking effect of the interface are discussed. To demonstrate chemically selective patterning, high‐resolution multi‐wavelength patterns were created in the PMMA/PAN bilayer system.     

Determination of the effective refractive index of porous silicon/polymer composite films

The equation for calculating the effective refractive index of porous silicon inserted polymer was obtained by three-component Bruggeman effective medium model. The dependence of the effective refractive index of porous silicon/polymer composite films on the polymer fraction with various initial porosity was given theorically and experimentally respectively. The porous silicon and polymer polymethylmetacrylate based dispersive red one (PMMA/DR1) composite films were fabricated in our experiments. It is found that the measured effective refractive index of porous silicon inserted polymer was slightly lower than the calculated result because of the oxidization of porous silicon. The effective refractive index of oxidized porous silicon inserted polymer also was analyzed by four-component medium system.     

Hologram Recording in Various Glass Plates by Corona Charging

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.