Electromagnetic Wave Localization in Photonic Fractals

“3D fractal structures, which we have named photonic fractals, can strongly localize electromagnetic
wave with a specific wavelength associated with the geometry and physical properties of the fractal
structures. The photonic fractals can be fabricated with various materials including polymers,
ceramics, metals, and their composites. The localization mechanism in a photonic fractal with
self-similar structure is essentially different from the localization in a photonic crystal with a
periodic structure. This new material is considered to be applicable in a wide area of communication,
information, energy, sensing, medical care, and other fields”.

“Fractal is the term which describes rough and irregular structures with self-similarity such that the local
configuration is similar to the whole configuration [1]. Fractal structures have no periodicity and no translational
symmetry like crystal structures. Interaction of optical, electromagnetic, and acoustical waves with fractal or
quasi-periodic structures has been of theoretical and practical interest in recent years. However, studies
concerning the localization of electromagnetic waves in these structures have been restricted to one or two
dimensions [2-6]. A 3D fractal structure is necessary to completely localize light or electromagnetic waves.
Nevertheless, 3D fractal structures have not been fabricated probably due to the difficulties of construction.
Recently, we have succeeded in the fabrication of 3D fractal structures called Menger sponges, which are made
of dielectric media such as epoxy and ceramics, and found a significant feature in that the incident microwave
is strongly localized in the fractal with very large attenuations both in reflectance and transmittance at the
same frequency [7,8]. We have named such fractals as photonic fractals because no other materials which can
localize electromagnetic waves in the 3D fractal form is known. Photonic fractals may have large potential
applications in communication, information, energy, sensing, medical care, and other fields. This paper reports
on the design and fabrication of 3D fractals using CAD/CAM stereolithography, electromagnetic wave
responses for such fractal structures made of polymer, ceramic, and metal materials, together with expected

READ FULL ARTICLE HERE: http://www.jwri.osaka-u.ac.jp/publication/trans-jwri/pdf/341nmscp-takema.pdf

Written By: MIYAMOTO Yoshinari *, KIRIHARA Soshu **, WADA TAKEDA Mitsuo ***, HONDA Kastuya ***

Kami Export – 341nmscp-takema