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题名	远场生物光学成像与相关的非线性光学研究
作者	毛峥乐
学位类别	硕士
答辩日期	2009
授予单位	中国科学院上海光学精密机械研究所
导师	程亚
关键词	光学超分辨，双色单光子显微术，同轴双色双光子显微术，纳米银颗粒，光学非线性
其他题名	Far-field Optical Bio-imaging and Relevant Study of Optical Nonlinearity
中文摘要	本论文将主要分为两大部分。第一部分关于远场光学荧光显微术，首先系统阐述远场超分辨显微术的现有方法，从多角度对分辨率问题进行深入分析。着重论述可逆光敏荧光蛋白Dronpa的性质，并基于它的性质提出了一种全新的双色单光子超分辨显微术。同时提出一种适用于高散射生物组织成像的同轴双色双光子显微术在细胞深层扫描技术的应用，并进行蒙特卡洛模拟。 第二部分将阐述纳米金属颗粒尤其是纳米银颗粒的研究现状。详细讨论纳米银颗粒的表面等离子体共振现象及其应用，着重阐述纳米银颗粒乙醇溶液的热致光学非线性现象的研究结果，实验获得较大的热致三阶非线性系数。实验证明了纳米银颗粒在光路保护，光束平整化和光开关等光学器件中的应用价值。 本论文主要取得了以下几个方面的进展： 1，远场光学显微术原理分析。系统分析了现有各种远场光学显微术的原理、特点，并相应提出了改进方案。经分析指出：由于Abbe衍射极限是线性光学的产物，因此基于线性光学原理的远场光学显微术难以真正突破Abbe衍射极限。只有引入非线性效应，才能获得超越衍射极限的分辨率。利用荧光分子之间的荧光能量共振转移以及单分子定位技术，甚至可以达到纳米级的分辨率。 2，提出一种基于可逆光敏荧光蛋白Dronpa的双色单光子超分辨显微术。 基于可逆光敏荧光蛋白Dronpa仅在两束光重叠区域才能实现荧光激发的性质，采用一束敏化光和一束激发光使二者焦点仅部分重叠，有效减小荧光激发体积和背景噪声，从而提高光学分辨率。数值计算表明，双色单光子超分辨显微术的横向分辨率相对于传统的宽场显微术提高1.55~2.81倍。 3，提出一种同轴双色双光子显微术，理论上证明了同轴双色双光子激发可以在三维成像中达到更深的透射深度。同轴双色双光子显微术采用一束环形光和一束圆形光作为激发光同轴传播，两束光在达到二者共有焦点前不重叠，仅在共有焦点处重叠从而抑制背景噪声的产生。利用蒙特卡洛模拟表明：相对于传统双光子显微术，同轴双色双光子显微术在高散射介质中具有更深的透射深度。 4，研究纳米银颗粒乙醇溶液的光学非线性特性。首次采用488nm的连续激光照射纳米银颗粒乙醇溶液，测量该混合溶液的热致三阶非线性折射率约为-1.941×10-7cm2/W。利用纳米银颗粒乙醇溶液较高的三阶非线性折射率导致热致负透镜效应和空间自相位调制现象，讨论和实验证明了纳米银颗粒乙醇溶液在光路保护，光束平整化和光开光等光学器件应用的价值。
英文摘要	The thesis is mainly composed of two parts. One part is about far-field optical microscopies. Firstly, almost all popular far-field optical super-resolution microscopies are presented and the concept of resolution has been discussed thorough from different points of view. Then much attention is paid on the properties of a reversible photoactivated fluorescent protein-Dronpa and a new super-resolution microscopy is proposed. Thirdly, we show a new microscopy with enhanced penetration for biological tissue imaging, which is simulated by Monte Carlo Method. The other part is about metal nanoparticles, especially, silver nanoparticles and surface plasmon resonance (SPR). We show our results of study on ethonal solution doped with silver nanoparticles. A large thermal-induced third-order nonlinear refractive index is obtained. Obvious spatial self-phase modification and thermal-induced negative lens effect are observed and their applications such as optical protection, beam flattening and optical switch are demonstrated in our experiments. The research progresses in this thesis are shown as follows: 1, almost all popular far-field optical super-resolution microscopies are reviewed and principles of super-resolution are discussed. We conclude that diffraction barrier is hard to be broken until nonlinear optical effects are introduced into far-field optical microscopy since the diffraction limit is based on linear optics. Furthermore, the barrier of diffraction-limit can also be broken by novel technologies based on fluorescence resonance energy transfer and high-accuracy localization of fluorophores, by which molecules can be positioned with a resolution of several nanometers. 2, a new two-color one-photon microscopy based on a novel photoactivated fluorescent protein-Dronpa is proposed. Based on the fact that Dronpa is hard be excited unless it is activated before, we use one photoactive beam and another excitation beam, and make their focal point overlap partly, which effectively decreases excitation volume and background noise to improve optical resolution. It is demonstrated the lateral resolution of our new two-color one-photon microscopy is 1.55~2.81 times better than that of traditional wide-field microscopy. 3, a new concentric two-color two-photon (C2C2P) microscopy is proposed. We theoretically demonstrate that enhanced penetration depth in three-dimensional multiphoton microscopy can be achieved using C2C2P fluorescence excitation in which the two excitation beams are separated in space before reaching their common focal spot. Monte Carlo simulation shows that, in comparison with the one-color two-photon excitation scheme, the C2C2P fluorescence microscopy provides a significantly greater penetration depth for imaging into a highly scattering medium. 4, to our best knowledge, it is the first time to study the optical nonlinearity of ethonal doped with silver nanoparticles with irradiation of CW 488nm laser. A large thermal-induced third-order nonlinear refractive index up to -1.941×10-7cm2/W is obtained, which may result from SPR enhancement effect of silver nanoparticles as well as high thermo-optic coefficient and low thermal conductivity of ethanol. Obvious spatial self-phase modification and influence of thermal-induced negative lens effect are observed when a beam is propagating through this solution, indicating promising applications such as optical protection, beam flattening and optical switch and so on.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16422]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	毛峥乐. 远场生物光学成像与相关的非线性光学研究[D]. 中国科学院上海光学精密机械研究所. 2009.

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