Structural Joining of Ceramics Nanoparticles: Development of Photonic Crystals for Terahertz Wave Control by Using Micro Stereolithography

Abstract

Structural joining is new concept of materials processing to create novel functional materials with special patterns and morphologies. Nanometer sized ceramics particles are bound continuously with resin materials solidified by laser beam irradiations to form micrometer order structures exactly. In this paper, fabrication processes of alumina photonic crystals with a periodic diamond structure will be introduced. Periodic arrangements of dielectric constants can control electromagnetic waves in terahertz frequency ranges through spatial wave diffractions. Three dimensional dielectric lattices were designed by using graphical application of a computer aided designing (CAD) software, and acrylic diamond structures with alumina nanoparticles dispersion were formed by using micro stereolithography (μ-STL) of a computer aided manufacturing (CAD) system. Fabricated precursors were dewaxed and sintered in the air to obtained full ceramics photonic crystals. The terahertz wave properties were measured by terahertz time domain spectroscopy (TDS) device. A complete photonic band gap to reflect the terahertz wave perfectly was observed, and showed good agreement with a theoretical simulation of plane wave expansion (PWE) method. Moreover, localization of the terahertz wave were observed in point or plane defects introduced into the diamond photonic crystals trough an electromagnetic field analysis of transmission line modeling (TLM) method.

Keywords

• photonic crystal
• band gap
• dielectric material
• terahertz wave
• stereolithography