Development of scanning near-field optical microscope with a micro rasonator and a optical resonator

扫描近场光学显微镜有多种类型，具有不同的近场产生方法。但它们大多不能同时接受高空间分辨率和样品材料的多样性。在本报告中，我们提出的由微谐振器和微凸起组成的原型SNOM探头可以解决这一问题。必须应用于光波导和光存储器的光学微制造需要近场局部化和增强。如上所述，我们为这些目的设计和创造了一种新的探测器。一系列的试验性实验表明，探头周围有许多杂散光或光散射的来源。因此，用手拉伸的单模光纤，在CO2激光照射下加热，形成球面微谐振腔。因此，玻璃谐振器有一个支撑辐条。轮辐的末端用粘合剂固定，谐振器安装在石英衬底上，与Illumi…耦合更多的国家光，没有任何意想不到的光源。在下一步中，用HeCd激光照明的焦点光刻胶创建微突起。激光是用显微镜物镜聚焦的，因此凸起的尺寸约为1微米。通过扫描钛宝石激光器的波长，观察到微凸体的光散射，因为适当的波长会在微谐振腔内引起光学共振。这一结果证实了原型探头可能作为SNOM探头的作用。我们用该探头作为标准样品扫描了商业光盘的表面。在CD表面，记录了许多众所周知的大小(深度=100 nm，宽度=500-800 nm，长度=870-3180 nm)的凹坑。结果，凹坑被清理得很清楚，我们证实了原型探针的有效性。进一步的改进将通过计算机辅助设计来优化探头的结构。我们开发了一个三维边界元方法的计算机模拟程序来分析电磁波在探头周围的传播。该程序模拟了样品接近探头的近场现象。较好地模拟了随着探头与样品之间距离的减小，凸起的光散射增加的现象。此外，还发现了凸起的形状和材料对光散射的影响。这一结果表明，光学共振在尺寸小于光波长的突起中具有重要意义。我们认为，本研究创造了一种用于SNOM的新型探头的原型，研究结果为进一步改进用于光学纳米制造的SNOM探头提供了一个两极星。较少

There are many types of Scanning Near-field Optical Microscopes with differenet methods of near-field creation. But most of them can not accept both high spatial resolutions and variety of sample materials. In this report, our proposal of a prototypical SNOM probe consists of a micro resonator and a micro protrusion may solve the problem.Optical micro fabrication which has to be applied to optical waveguides and optical memories needs localization and enhancement of near-field. We have designed and created a new probe, as desribed above, for these purposes. A series of trial experiments showed that there are many sources of stray lights or light scattering around the probe. So a spherical micro resonator is formed from an single mode optical fiber, which was stretched by hand and heated with CO2 laser irradiation. As a result, the glass resonator had a supporting spoke. The end of the spoke was fixed with bond, and the resonator was installed on the quartz substrate to couple an illumi … More nation light without any unexpected light sources. In the next step, the micro protrusion was created from a photoresist with a focal spot of HeCd laser illumination. The laser was focused with a microscope objective, therefore the size of the protrusion was about 1 micron. The light scattering from the micro protrusion was observed by scanning the wavelength of Ti : Sapphire laser, because an appropriate wavelength caused an optical resonance inside the micro resonator. This result confirmed that the prototypical probe might acts as a SNOM probe.We scanned a surface of commercial compact disc as a standard sample with this probe. On the CD surface, there are many pits recorded with well-known sizes (depth=100nm, width=500-800nm, length=870-3180nm). As a result, the pits were sanned clearly, and we confirmed the validity of the prototypical probe. Further improvements will be achieved by an optimization of the probe configuration with computer aided designing as follows.We developed a computer simulation code with three dimensional boudary element method to analyze an electromagnetic wave propagation around the probe. This code simulated a near-field phenomenon of approaching of a sample to a probe. The increase of light scattering from the protrusion with decreasing the distance between probe and sample was simulated well. And also, the influence of the shape and the material of the protrusion on the light scattering was found. This result expected an importance of the optical resonance in the protrusion which size is below the light wavelength.We conclude that this research created an prototypical novel probe for SNOM, and the research results gave us an polestar in further improvement of the SNOM probes for optical nano fabrication. Less