Near-field optical and atomic-force microscopy by use of the laser trapping technique of a probe

使用探针激光捕获技术的近场光学和原子力显微镜

• 批准号: 07405005
• 负责人: KAWATA Satoshi
• 金额: $ 22.21万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07405005/
• 关键词: laser trapping; near-field optics; friction force; FDTD method; 3D micro-fabrication; UV-photopolymerizable resin; two photon absorption; レーザトラッピング; 光の放射圧; 紫外線効果樹脂; 自己形成過程; レーザー・トラッピング; ニアフィールド顕微鏡

We developed a scanning friction-force microscope which uses a small sphere trapped and scanned by laser beam. The force can be detected as position shift of the sphere, during the sample scanning. The system consists of an inverted microscope, a scanning stage, a near-infrared laser (Nd : YAG,2W), illumination optics, a position detector, and a computer for control. The detection limit of the friction-force with the system was 1.0(]SY.+-。[)0.2pN when we observed the surface of glass or PMMA.We added detection optics for near-field optical signal to the system in order to realize a near-field optical microscope. Since the microscope uses a laser trapped probe, which is trapped by pico-Newton-order force in water, the system has advantages as follows : 1) it gives little damage to the sample, 2) the distance between the sample surface and the probe is constant, and 3) the spatial resolution can be controlled by choosing an appropriate size of the probe. By using this system we trapped n … More ot only dielectric spheres but also metallic spheres. The metallic sphere has high scattering efficiency and provides high signal-to-noise ratio. Moreover small sphere (phi40nm) attains high spatial resolution.We developed three-dimensional microfabrication technique using two-photon absorption. Two-photon absorption process makes it possible to stiffen only small spot near the focal point. We estimated that lateral and axial resolutions are 0.6mum and 1.0mum respectively, by optimizing pulse-width and real power of mode-locked Ti : Sapphire laser (790nm). This system provides one-order higher resolution than conventional systems. Therefore this technique is available to make a probe, that can be stably and precisely trapped by a laser beam.We also showed that finite-difference time-domain (FDTD) method is effective to amalyze the photon force in near-field. We succeeded in calculation of the irradiation forces (=trapping forces) of evanescent or propagation light field to any shapes or materials probes. We investigated the size, the material, and the shape of the probe which is suitable for the microscope we developed. Less

我们研制了一种扫描摩擦力显微镜，它利用一个小球体被激光捕获和扫描。在样品扫描过程中，可以通过球体的位置移动来检测力。该系统由倒置显微镜、扫描工作台、近红外激光器(2W)、照明光学系统、位置探测器和控制计算机组成。该系统对摩擦力的检测下限为1.0(+-)。[)0.2pN。为了实现近场光学显微镜，我们在系统中加入了近场光信号检测光学元件。由于显微镜使用的是被皮牛顿级力捕获的激光探头，因此该系统具有以下优点：1)对样品损伤小；2)样品表面到探头的距离是恒定的；3)通过选择合适的探头尺寸可以控制空间分辨率。通过使用这个系统我们捕获了n个…更多的不仅是介电球，还有金属球。金属球体具有高散射效率和高信噪比。此外，小球体(Phi40 Nm)具有很高的空间分辨率。我们开发了基于双光子吸收的三维微细加工技术。双光子吸收过程使焦点附近的小光斑变硬成为可能。通过优化锁模钛宝石激光器(790 Nm)的脉宽和实际功率，估算出横向和轴向分辨率分别为0.6um和1.0um。该系统的分辨率比传统系统高一个数量级。因此，这项技术可以用来制作能够稳定、精确地被激光捕获的探测器。我们还表明，时域有限差分(FDTD)方法是分析近场光子力的有效方法。我们成功地计算了瞬变或传播光场对任何形状或材料的探头的照射力(=捕获力)。我们研究了适合于我们研制的显微镜的探头的尺寸、材料和形状。较少

项目成果

H.Kano and S.Kawata: "Grating-coupled surface plasmon for measuring the refractive index of a liquid sample" Jpn.J.Appl.Phys.34. 331-335 (1995)

H.Kano 和 S.Kawata：“用于测量液体样品折射率的光栅耦合表面等离子体”Jpn.J.Appl.Phys.34。

S.Maruo: "Two-photon-absorbed photopolymeriazation for three-dimensional microfabrication" Proc.IEEE 10th Int.Workshop on MEMS97. 97CH36021. 169-174 (1997)

S.Maruo：“用于三维微加工的双光子吸收光聚合”Proc.IEEE 10th Int.Workshop on MEMS97。

H.Furukawa and S.Kawata: "Local field enhancement with anapertureless near-microscope probe" Opt.Commun. (accepted for publication).

H.Furukawa 和 S.Kawata：“使用无孔近显微镜探头进行局部场增强”Opt.Commun。

H.Kano: "Two-phonton-excited fluorescence enhanced by a surface plasmon" Opt.Lett.21. 1848-1850 (1996)

H.Kano：“表面等离子体增强双光子激发荧光”Opt.Lett.21。

S.Kawata and T.Tani: "Optically driven Mie particles in an evanescent field along a channeled waveguide" Opt.Lett.21. 1768-1770 (1996)

S.Kawata 和 T.Tani：“沿着通道波导的渐逝场中的光驱动米氏粒子”Opt.Lett.21。