JHE Wonho Seoul National University Department of Physics, 理学部, 助教授
堀 裕和 山梨大学, 工学部, 助教授 (10165574)
北原 和夫 東京工業大学, 理学部, 教授 (20107692)
KITAHARA Kazuo Tokyo Institute of Technology, Faculty of Science
HORI Hirokazu Yamanashi University, Faculty of Engineering
(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
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 guidance
OHTSU 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.