Research on Millimeter-Wave and Submillimeter-Wave Scanning Near-Field Microscopy

毫米波和亚毫米波扫描近场显微镜研究

基本信息

批准号：
13650365
负责人：
NOZOKIDO Tatsuo
金额：
$ 2.24万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

The objective of this research project is to demonstrate the new type of scanning near-field microscopy, i.e. scanning near-field anisotropy microscopy (SNAM) and to quantify images obtained from the scanning near-field microscope system using a metal slit-type probe which we have proposed and developed, in order to visualize physical parameters of objects such as refractive index and refractive index anisotropy, in the millimeter-wave and submillimeter-wave regions. The results obtained in the term of the project follow.In order to quantify images more precisely in the millimeter- and submillimeter-wave regions, we have proposed, designed, and made a new type of sample base to reduce needless signal fluctuations originated from surface modes. We have successfully demonstrated the effectiveness of this new hardware and found that the signal fluctuation reduces to less than 10% of the previous one. This result means that the microscope system we have developed have a potential to give a limiting refractive index sensitivity of better than Δn/n〜0.1. Furthermore, in order to visualize physical parameters of objects, we have proposed an equivalent circuit to describe the interaction between the probe and object, and succeeded to demonstrate the validity of the circuit by computer simulation using a finite element method and by experiments in the millimeter-wave region.We have tried to visualize anisotropy of objects by including an anisotropy model derived from two-dimensional refractive idex ellipsoid in the image reconstruction process using a block-gradient method, which is a kind of iterative reconstruction technique. An isotropic metal patch, a wire gird with large anisotropy, and a LiNbO_3 crystal which is a typical anisotropic dielectric, were experimentally tested in the millimeter-wave region and the images were reconstructed. We have found that anisotropy of these objects are clearly imaged with a resolution of less than 1/10 of the radiation wavelength used.

该研究项目的目的是证明新型的扫描近场扫描类型，即扫描近场各向异性显微镜（SNAM），并使用金属缝隙型探针从扫描的近场显微镜系统中获得的图像进行量化，我们提出和开发了诸如物理参数的物理参数，以形象划分物理参数，以形象划分物的物理参数。毫米波和亚毫米波区域。我们已经提出，设计并制造了一种新型的样品库，以更准确地量化图像，以更精确地量化图像，以更准确地量化图像，以更准确地量化图像。我们已经成功证明了这款新硬件的有效性，并发现信号波动减少到了前一个硬件的不到10％。该结果意味着我们开发的显微镜系统具有限制折射率敏感性的潜力，其灵敏度优于Δn/n〜0.1。此外，为了使对象的物理参数可视化，我们提出了一个等效电路来描述探针和对象之间的相互作用，并成功地通过使用有限元元素方法来证明电路通过计算机模拟的有效性，并通过有限的实验在毫米波区域中进行实验。我们试图通过包括两种模型的远离元素的偏差，以远离两种元素的偏射，并源自两种模型。使用块梯度方法的图像重建过程，这是一种迭代重建技术。在毫米波区域进行了实验测试，并重新构造了各向同性的各向同性金属贴片，具有大型各向异性的电线和典型各向异性词典的Linbo_3晶体。我们发现，这些物体的各向异性清楚地以小于1/10所用的辐射波长的1/10分辨率进行成像。