Near-Field Optics and Its Applications

(1)近场光学理论工作：开发了高分辨率近场光学显微镜，用于评价近场基本特性。对于这台显微镜，他采用化学蚀刻工艺将光纤芯削尖，并涂覆金属薄膜，从而实现了针尖直径为3nm的探针。他操作显微镜系统来评估近场对颗粒大小、入射光的偏振等的依赖关系。进一步，他测量了该系统的系统功能，估计该系统的分辨率高达甚至高于0.8 nm。在此基础上，通过改进化学蚀刻工艺，制备了通量为10^<-3>的高灵敏度光纤探针。该探针用于高密度光存储和功能光子器件的实现的初步研究。基于Mie散射理论，JHE获得了近场特性，即尺寸相关的局域化和探针与样品之间的共振现象。利用像偶极子法分析了入射光的偏振关系。KITAHARA提出通过在平面上产生的两个倏逝场之间的干涉来控制近场的偏振状态。他讨论了这种新型的倏逝场在表面科学中的应用。HORI发展了用一组球面函数展开任意函数的方法，用于近场光学理论。此外，通过对量子力学基本方程的类比，他确定了可以清楚地看到近场光学现象的粒径范围。(2)原子导通实验工作：计算了高真空中空纤维中导通原子的电位分布。他设计了将导光耦合到圆柱芯中空光纤的光学系统和检测通过光纤传输的原子的光电离系统。通过组装这些系统，他成功地引导Rb原子通过中空纤维。当光纤的中空直径为7微米，长度为3厘米，导光功率为250兆瓦时，传输的原子数是无光时的20倍。评估了制导特性对若干参数的依赖关系。此外，作为这种引导的应用，有选择地引导了Rb原子的一个同位素。JHE估计了中空纤维内表面吸附原子的空腔量子电动力学效应的大小。将该估计用于原子制导系统的设计。HORI采用无多普勒光谱学来测试原子与光学近场之间的共振相互作用。少

(1) Theoretical works on near field optics :OHTSU developed a high resolution near-field optical microscope to evaluate basic characteristics of near-field. For this microscope, he sharpened the fiber core by chemical etching process and coated the metallic film so as to realize a probe with the tip diameter of 3 nm. He operated the microscope system to evaluate the dependencies of near-field on the particle size, polarization of the incident light, and so on. Further, he measured the system function of this system and estimated the resolution as high as or even higher than 0.8 nm. Further, he fabricated a high-sensitivity fiber probe with the throughput of 10^<-3> by modifying the chemical etching process. This probe was used for the preliminary studies on high-density optical storage and realization of functional photonic devices.JHE obtained the properties of near-field, i.e., sizedependent localization and resonance phenomenon between the probe and sample based on the Mie scatterin … More g theory. Further, he has analyzed the dependency of polarization of the incident light by the image dipole method.KITAHARA proposed controlling polarization state of the near-field by interference between the two evanescent fields originally generated on a planar surface. He discussed application of such a novel evanescent field on surface science.HORI developed the method of expanding arbitrary function by a set of spherical function, which is used for near-field optical theory. Further, by an analogy of basic equation of quantum mechanics, he identified the range of the particle size in which the near-field optical phenomena are clearly seen.(2) Experimental works on atom guidanceOHTSU calculated the potential profile of guiding atoms through a hollow fiber in high vacuum. He designed optical system for coupling the guiding light to the cylindrical-core hollow fiber, photo-ionization system for detecting the atoms transmitted through the fiber. By assembling these systems, he has succeeded in guiding Rb atoms through the hollow fiber. The number of transmitted atoms was 20 times that without the light when the hollow diameter and length of the fiber were 7-micron and 3 cm, respectively, and the guiding light power was 250 mW.Dependency of guidance characteristics on several parameters were evaluated. Further as an application of this guidance, one isotope of Rb atoms were selectively guided.JHE has estimated the magnitude of cavity quantum electrodynamic effect, which can adsorb the atoms on the inner surface of the hollow fiber. This estimation was used for designing the atom guidance system.HORI carried out Doppler-free spectroscopy for testing the resonance interaction between atoms and optical near-field. Less