Develoment of a Ultra-Minute Laser Scanning Microscope and Novel Optical Properties

超微型激光扫描显微镜的开发和新颖的光学特性

基本信息

批准号：
11490008
负责人：
TOSHIRO Tani
金额：
$ 9.6万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

We have developed an ultra-minute simple scanning laser microscope which is of basically confocal type and operates at cryogenic temperature with high efficiency and resolution without laborious adjustment. A gradient index rod-type micro lens with suitable length can operate as an objective lens with no working distance because an incident parallel beam passed through one side of the rod lens focuses on the other side plane. Due to the solid immersion lens (SIL) effect, this rod lens enhances the resolution of microscope and also collect efficiently the fluorescence emitted by a sample directly attached on the focal plane. This is the reason why we proposed the gradient index solid immersion lens scanning microscope (grin-SBL microscope) for the study of optical properties of condensed matter.In spite of high efficiency, traditional optical microscope has a limit of resolution due to the diffraction of light. On the other side, near field scanning optical microscope(NSOM) beyond this … More limit in principle must operate instead at very low signal intensities and has not been put into practical use sufficiently. The grin-SBL microscope we have developed here fills up these deficiencies and proved to be very useful for specified purposes.The performance was demonstrated on single molecules of terrylene in a dodecane crystal at 1.6 K and on molecular J aggregates by halogenated pseudoisocyanine in poly (vinylsulfate) thin film. In the latter system, while spectral characteristics of sharp and intense J-band shifted to the red from that of the monomers due to the formation of quasi-1D Frenkel exciton is most notable, a relation to its microscopic structures is not clear yet. To get insight into this issue, we have tried to observe local reflection spectra of the J-aggregates fibril-shape structures provided in thin PVS polymer films, preliminary results of which is presented in connection with their microscopic morphological observations and exciton-polariton model is proposed.We have also started a preparation of organic-inorganic nano-composite nanocrystals of semiconductor CdSe with synthetic chemical ways, whose optical properties are characterized with quasi zero dimensional Wannier excitons. To improve optical properties of CdSe nanocrystals, passivation with a wider gap material ZnS was performed. Although the nanocrystal sizes are limited to the range of 2〜5nm in diameter, the quantum efficiency of fluorescence greater than 50% is obtained. Less

我们开发了一种超微小简易扫描激光显微镜，它基本上是共焦型的，在低温下工作，效率高，分辨率高，无需费力调整。适当长度的梯度折射率棒型微透镜可以作为物镜使用，无需费力调整。由于固体浸没透镜（SIL）效应，入射平行光束穿过棒状透镜的一侧聚焦在另一侧平面上，因此该棒状透镜提高了显微镜的分辨率，并且还可以有效地收集显微镜发出的荧光。样品直接附着在焦平面上。这就是我们提出梯度折射率固体浸没透镜扫描显微镜（grin-SBL显微镜）来研究凝聚态物质光学性质的原因。尽管传统光学显微镜效率很高，但由于光的衍射，其分辨率受到限制。另一方面，超过这个限制的近场扫描光学显微镜（NSOM）原则上必须在非常低的信号强度下工作，并且尚未充分投入实际使用，我们在这里开发的grin-SBL显微镜填补了这一点。上这些该性能在 1.6 K 十二烷晶体中的三萘嵌苯单分子和聚（硫酸乙烯酯）薄膜中的卤化假异氰酸酯分子 J 聚集体上得到了证明。由于准一维弗兰克尔激子的形成，尖锐而强烈的 J 带的特征从单体的带移至红色，这是最显着的，与其相关为了深入了解这个问题，我们尝试观察 PVS 聚合物薄膜中 J 聚集体纤维状结构的局部反射光谱，并结合其微观形态给出了初步结果。我们还开始用化学合成方法制备有机-无机纳米复合半导体CdSe纳米晶，其光学性质具有准零维特征。为了改善CdSe纳米晶的光学性能，采用更宽的间隙材料ZnS进行钝化，尽管纳米晶尺寸限制在2~5nm范围内，但荧光量子效率却大于50%。