Terahertz Wave Properties of Ceramic Photonic Crystals with Graded Structure Fabricated by Using Micro-Stereolithography

2009 ◽  
Vol 631-632 ◽  
pp. 299-304 ◽  
Author(s):  
Soshu Kirihara ◽  
Toshiki Niki ◽  
Masaru Kaneko
Keyword(s):  
Electromagnetic Wave ◽  
Photonic Crystals ◽  
Photonic Band Gap ◽  
Three Dimensional ◽  
Expansion Method ◽  
Terahertz Wave ◽  
Diamond Structure ◽  
Terahertz Time Domain Spectroscopy ◽  
3D Cad ◽  
Wave Properties

Fabrication and terahertz wave properties of alumina micro photonic crystals with a diamond structure were investigated. The three-dimensional diamond structure was designed on a computer using 3D-CAD software. Acrylic diamond structures with alumina particles dispersion were formed by using micro-stereolithography. Fabricated precursors were dewaxed and sintered in the air. The electromagnetic wave properties were measured by terahertz time-domain spectroscopy. A complete photonic band gap was observed at the frequency range from 0.40 to 0.47 THz, and showed good agreement with the simulation results calculated by the plane wave expansion method. Moreover, a localized mode was obtained by introducing a plane defect between twinned diamond structures. The one-way transmission of the electromagnetic wave was realized by using this twinned photonic crystal with the graded diamond structure. They corresponded to the simulation by the transmission line modeling (TLM) method.

Terahertz wave properties of alumina microphotonic crystals with a diamond structure

2008 ◽  
Vol 23 (4) ◽  
pp. 1036-1041 ◽  
Author(s):  
Hideaki Kanaoka ◽  
Soshu Kirihara ◽  
Yoshinari Miyamoto
Keyword(s):  
Photonic Band Gap ◽  
Three Dimensional ◽  
Expansion Method ◽  
Linear Shrinkage ◽  
Terahertz Wave ◽  
Diamond Structure ◽  
Terahertz Time Domain Spectroscopy ◽  
3D Cad ◽  
Unit Cells ◽  
Wave Properties

Fabrication and terahertz wave properties of alumina microphotonic crystals with a diamond structure were investigated. The three-dimensional diamond structure was designed on a computer using 3D-CAD software. The designed lattice constant was 500 μm. The structure consisted of 8 × 8 × 4 unit cells. Acrylic diamond structures with an alumina dispersion of 40 vol% were formed by using microstereolithography. Fabricated precursors were dewaxed at 600 °C and sintered at 1500 °C. The linear shrinkage ratio was about 25%. The relative density reached 97.5%. The electromagnetic wave properties were measured by terahertz time-domain spectroscopy. A complete photonic band gap was observed at the frequency range from 0.40 THz to 0.47 THz, and showed good agreement with the simulation results calculated by the plane wave expansion method. Moreover, localized modes were obtained at the frequencies 0.42 THz and 0.46 THz by introducing an air defect in the diamond structure. They corresponded to the simulation by the transmission line modeling method.

Electromagnetic properties of photonic crystals with diamond structure containing defects

2003 ◽  
Vol 18 (9) ◽  
pp. 2214-2220 ◽  
Author(s):  
Shingo Kanehira ◽  
Soshu Kirihara ◽  
Yoshinari Miyamoto ◽  
Kazuaki Sakoda ◽  
Mitsuo Wada Takeda
Keyword(s):  
Photonic Crystals ◽  
Band Gap ◽  
Photonic Band Gap ◽  
Three Dimensional ◽  
Expansion Method ◽  
Electromagnetic Properties ◽  
Diamond Structure ◽  
Multiple Reflections ◽  
Air Cavity ◽  
Photonic Band

Three-dimensional photonic crystals with a diamond structure, which are composed of the TiO2-based ceramic particles dispersed in an epoxy lattice, were fabricated by stereolithography. The diamond structure showed a photonic band gap in the 14.3–17.0 GHz range along the Γ-K 〈110〉 direction, which is close to the band calculation using the plain wave expansion method. Two types of lattice defects—air cavity and dielectric cavity—were introduced into the diamond structure by removing a unit cell of diamond structure or inserting a block of the lattice medium into the air cavity. The transmission of millimeter waves affected by multiple reflections at the defects was measured in the photonic band gap. Resonant frequencies in the defects were calculated and compared with the measurement results.

scholarly journals Electromagnetic Wave Diffractions in Ceramic/Polymer Photonic Crystals with Three-Dimensional Diamond Structure

2003 ◽  
Vol 111 (1295) ◽  
pp. 471-478 ◽  
Author(s):  
Soshu KIRIHARA ◽  
Mitsuo TAKEDA ◽  
Kazuaki SAKODA ◽  
Yoshinari MIYAMOTO
Keyword(s):  
Electromagnetic Wave ◽  
Photonic Crystals ◽  
Three Dimensional ◽  
Diamond Structure

Electromagnetic properties of three-dimensional woven carbon fiber fabric/epoxy composite

2017 ◽  
Vol 88 (20) ◽  
pp. 2353-2361 ◽  
Author(s):  
Wei Fan ◽  
Dan-dan Li ◽  
Jia-lu Li ◽  
Juan-zi Li ◽  
Lin-jia Yuan ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Fiber ◽  
Electromagnetic Interference ◽  
Three Dimensional ◽  
Woven Fabric ◽  
Epoxy Composites ◽  
Woven Composites ◽  
Carbon Fiber Fabric ◽  
Fiber Fabric ◽  
Wave Properties

To investigate the reinforcement architectures effect on the electromagnetic wave properties of carbon fiber reinforced polymer composites, three-dimensional (3D) interlock woven fabric/epoxy composites, 3D interlock woven fabric with stuffer warp/epoxy composites, and 3D orthogonal woven fabric/epoxy composites were studied by the free-space measurement system. The results showed that the three types of 3D woven carbon fiber fabric/epoxy composites had a slight difference in electromagnetic wave properties and the absorption was their dominant radar absorption mechanism. The electromagnetic wave absorption properties of the three types of composites were more than 90% (below −10 dB) over the 11.2–18 GHz bandwidth, and more than 60% (below −4 dB) over the 8–12 GHz bandwidth. Compared with unidirectional carbon fiber reinforced plastics, the three kinds of 3D woven carbon fiber fabric/epoxy composites exhibited better electromagnetic wave absorption properties over a broadband frequency range of 8–18 GHz. Therefore, the three kinds of 3D woven composite are expected to be used as radar absorption structures due to their excellent mechanical properties and outstanding absorption capacity. The total electromagnetic interference shielding effectiveness of the three types of 3D carbon fiber woven composites are all larger than 46 dB over the 8–12 GHz bandwidth, which is evidence that the three types of 3D carbon fiber woven composites can be used as excellent shielding materials for electromagnetic interference.

Selective Transmission of Electromagnetic Wave by Using Diamond Photonic Crystals with Graded Lattice Spacing

2006 ◽  
Vol 45 ◽  
pp. 1139-1144
Author(s):  
Soshu Kirihara ◽  
Yoshinari Miyamoto
Keyword(s):  
Photonic Crystals ◽  
Band Gap ◽  
Electromagnetic Waves ◽  
Lattice Spacing ◽  
Three Dimensional ◽  
Dielectric Constants ◽  
Microwave Antenna ◽  
Diamond Structure ◽  
Band Calculation ◽  
Graded Lattice

Three-dimensional electromagnetic or photonic crystals with periodic variations of the dielectric constants were fabricated by using a rapid prototyping method called stereolithography. Millimeter-order epoxy lattices with a diamond structure were designed to reflect electromagnetic waves by forming an electromagnetic band gap in GHz range. Titania based ceramic particles were dispersed into the lattice to control the dielectric constant. The diamond lattice structures formed the perfect band gap reflecting electromagnetic waves for all directions. The location of the band gap agreed with the band calculation using the plane wave propagation method. The diamond structures with graded lattice spacing were successfully fabricated as well, resulting in the directional transmission of microwaves. The stretching ratio of the lattice spacing in the crystal structure was changed according to the electromagnetic band calculation. A microwave antenna head composed of the diamond structure with graded lattice spacing was fabricated which achieved the unidirectional transmission.

Sign in / Sign up

Export Citation Format

Share Document