Realization of nanometric optical functional devicesusing evanescentlignt localized in a subwavelendth three dimensional space

为了实现被动纳米器件，表面等离子体激元上的银薄膜，这是涂覆在玻璃板上的50 nm厚的激发。找到了均匀厚度的最佳涂覆条件，即，我们发现通过在银和玻璃之间夹置锗膜来增加均匀性。为了实现银薄膜的锐边，还开发了光掩模方法。结果，边缘的锐度增加了30倍。提出了将染料分子固定在针尖直径小于100 nm的锐尖光纤探针上的方法，实现了具有光学功能的探针针尖。通过使用来自这些染料分子的荧光进行成像实验，通过该成像实验证实了该探针对近场光学显微镜的效用，即，典型的非线性光学晶体生长在超平蓝宝石衬底上，以实现纳米区域的频率转换。对它们的特性，特别是第二代harominc进行了评价。用近场光学显微镜测量了生长的LN晶体（30nm × 20nm）的轮廓，证实其空间分辨率高达几nm。此外，还计算了入射光偏振态对成像的影响，得到了与理论结果相一致的结果。用脉宽100fs（波长800nm）的脉冲激光照射LN晶体，进行了二次谐波产生实验。用光子计数法测量了二次谐波信号，证实了每个LN晶体都能提供1位光学功能。通过实验和理论研究，为实现纳米光学功能器件奠定了基础。

To realize a passive nanometric device, surface plasmon was excited on a silver thin film with 50 nm thickness which was coated on a glass plate. Optimum condition for coating was found for homogeneous thickness, i.e., we found that the homogeniety was increased by sandwitching a gemanium film between silver and glass. Photomask method was also developedto realize a sharp edge of the silver tilm. As a result, sharpness of the edge was increased 30 times. Method of fixing dyemolecules on a sharpenedfiberprobe (the tip diameterless than 100 nm) was developedto realize a optically functional probe tip. Imaging experiment was carried out by using fluorescence from these dye molecules, by which utility of this probe to the near-field optical microscopy was confirmed Nano-crystals of Lithium niobate (LN), i.e., typical nonlinear optical crystals, were grown on an ultraflat sapphire substrate to realize frequency conversion in a nanometric region. Evaluation of their characteristics, and especially second harominc generation, were carried out. Profiles of grown LN crystals (30nmx20nm) were measured by a near-field optical microscope, by which spatial resolution as high as several nm was confirmed. Further, image depencency on the polarization state of the incidentlight was evaluated, and good agreement with the theoretical result was obtained. By irradiating the pulsedlaser light with 100fs pulse width (800nm wavelength) to the LN crystals, experiment of secondharmonics generation was carried out. Secondharmonic signal was measured by photon counting method, by which capability of offering 1-bit optical function to each LN crystal was confirmed Due to the experimental and theoretical studies carried out here, fundamentals for realizing nanometric optical functional devices were estabilished.