Authors: S. Kirihara, D. Sano, T. Niki, N. Ohta, Y. Takinami
Affilation: Osaka University, Japan
Pages: 223 - 226
Keywords: photonic crystal, terahertz waves
Electromagnetic waves in terahertz ranges are possible to harmonize with molecule vibrations of various saccharides or proteins, and expected to control the biological material syntheses through the frequency excitements. In this investigation, metals and ceramics photonic crystals with micro periodic structures were geometrically patterned by using stereolithography processes to resonate and localize the terahertz wave. In this process, photo sensitive resin with high viscosity were spread on a glass substrate with 10 µm in thickness by using a mechanical knife edge, and a two dimensional image of UV ray was exposed using digital micro-mirror device with 2 µm in part accuracy. Pure copper and alumina particles were dispersed into the resin paste. Through the layer by layer processes, three dimensional objects were formed successfully in micrometer orders. Dense copper and alumina photonic crystals could be obtained by dewaxing and sintering. The transmittances of electromagnetic waves for these fabricated crystal structures were measured by using a terahertz time domain spectroscopy system. The copper and alumina photonic crystals exhibited forbidden gaps in terahertz frequency ranges through Bragg diffraction. The measured results showed good agreements with the calculated ones by using transmission lime modeling method.