Three-dimensional Photonic Crystals (three-dimensional + photonic_crystal)

Distribution by Scientific Domains
Distribution within Polymers and Materials Science


Selected Abstracts


Dimer-Based Three-Dimensional Photonic Crystals

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Ian D. Hosein
Abstract The self-assembly of polystyrene dimer- and spherocylinder-shaped colloids is achieved via controlled drying on glass and silicon substrates. 3D monoclinic colloidal crystal structures are determined from scanning electron microscopy images of sections prepared using focused ion-beam (FIB) milling. Full photonic bandgaps between the eighth and ninth bands are found for a systematic range of colloidal dimer shapes explored with respect to the degree of constituent lobe fusion and radius ratio. The pseudogap between bands 2 and 3 for spherocylinder-based monoclinic crystals is also probed using normal incidence reflection spectroscopy. [source]


Microfabrication of Three-Dimensional Photonic Crystals of SiO2,Al2O3 Ceramics and Their Terahertz Wave Properties

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 3 2008
Weiwu Chen
Dense three-dimensional microphotonic crystals of SiO2,Al2O3 ceramics were fabricated using microstereolithography and successive sintering process. The forming dimensional tolerance for a 50 vol% ceramic paste is 10 ,m and sintering shrinkage is around 12%. Diamond-type photonic crystals with lattice constants of 500 and 125 ,m were formed and sintered successfully. The band gaps of the samples were measured and compared with the theoretically calculated band diagram. [source]


Log-Pile TiO2 Photonic Crystal for Light Control at Near-UV and Visible Wavelengths

ADVANCED MATERIALS, Issue 4 2010
Ganapathi Subramania
Three-dimensional photonic crystals with an omnidirectional bandgap at visible frequencies can have significant impact on solid-state lighting and solar-energy conversion. Using a procedure based on multistep electron-beam lithographic processing, a 9-layer log-pile photonic crystal is fabricated composed of 70-nm-wide titanium dioxide rods with 250-nm lattice spacing that exhibit a stacking direction bandgap between 400,nm and 500,nm (see image). [source]


Fabrication of 3D Photonic Crystals of Ellipsoids: Convective Self-Assembly in Magnetic Field

ADVANCED MATERIALS, Issue 19 2009
Tao Ding
Three-dimensional photonic crystals of ellipsoidal colloidal particles are prepared by direct convective self-assembly from suspension with the aid of a magnet. The magnetic field provides the orientational order, which is additionally needed for these colloidal particles with symmetry lower than spherical. The positional order is provided by the convection, just as for spherical colloids. [source]


Fabrication of Ceramic,Polymer Photonic Crystals by Stereolithography and Their Microwave Properties

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2002
Soshu Kirihara
Three-dimensional photonic crystals with periodic variations in the dielectric constant were fabricated using a stereolithographic rapid prototyping method. The structures were composed of millimeter-scale ordered epoxy lattices in which ceramic particles with high dielectric constants (such as silica and titania) were dispersed. These crystals were designed to reflect microwaves via the formation of photonic band gaps in a gigahertz range. The attenuation of transmission amplitude through the photonic crystals, which was measured as a function of frequency using a network analyzer, clearly showed the formation of band gaps in the microwave range. [source]