1999 Fiscal Year Final Research Report Summary
Elucidation of the behavior of photons in photonic crystals mechanically assembled from sub-micron particles
| Project/Area Number |
10650037
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied optics/Quantum optical engineering
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| Research Institution | TOHOKU UNIVERSITY (1999)
The University of Tokyo (1998) |
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Principal Investigator |
MIYAZAKI Hiroshi Graduate School of Engineering, Tohoku University, Associate Professor, 大学院・工学研究科, 助教授 (00134007)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Tomomasa Dep. of Mechano-Informatics, The University of Tokyo, Professor, 大学院・工学系研究科, 教授 (50235371)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Photonic crystal / Photonic band / Bragg diffraction / Mie scattering / Vector harmonics / Fine particle / Scanning electron microscope / Micro manipulator |
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| Research Abstract |
The behavior of photons in phonic crystals composed of micrometer-sized dielectric spheres has been investigated. The points of this research are the fabrication method based on mechanical manipulation, the experimental observation of diffraction of photons scattered from the crystals, and the theoretical analyses based on vector harmonics expansion.
By improving the vacuum system, manipulation technique of sub-micron particles has been established.
A selected area diffraction microscopy technique has been developed to examine the diffraction of light by the fabricated photonic crystals. By varying the lattice structure of crystals, incident direction of the light, and the wavelength, the scattered waves from the photonic crystals have been systematically observed. As a result, anomalous Bragg diffraction has been discovered for a certain incidence condition. The wavelength-dependence of the diffraction efficiency was very similar to that of the Mie scattering characteristics.
Furthermore, a calculation technique of finite arrays of spheres has been newly developed. Since the calculation of the electric fields inside the spheres has become possible, the behavior of photons can be clearly visualized. All the experimentally observed results were reproduced by the calculation. It has been clarified that the anomalous Bragg diffraction of photonic crystals originates from the characteristics of a unit array composed of only a few spheres. The Bragg diffraction of a photonic crystal arises only when the light propagation from spheres to spheres is accidentally enabled by the phase matching of vector harmonics mode. Moreover, a coherent backscatteing of photons from a photonic crystal has been observed in the calculation results.
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