Geometrical design of the spiral crystal selector can affect crystal orientation in the final single crystal structure. To achieve a better understanding of conditions associated with the onset of crystal orientation in a spiral crystal selector, temperature field was investigated using three-dimensional finite element method during the process. Different geometries of spiral crystal selec...

By adding a point defect to a photonic crystal structure, a microcavity can be made to trap electromagnetic energy with wavelength inside the photonic bandgap (PBG). This property together with other unique properties of photonic crystals enables us to control the propagation and spectrum of transmitted wave inside the photonic crystal waveguiding structures and to design and implement microsca...

The ability of photonic crystals to mold the flow of light in new ways can lead to a variety of novel and improved designs of optical nanocomponents and nanodevices in photonics. Two examples will be presented: a) Using linear materials, a polarization independent waveguide is designed in a 3D photonic crystal. It is demonstrated that this system provides lossless guiding of light at length-sca...

Single nonlinear optical crystals of L-Proline Potassium Bromide (LPPB) were synthesized and grown by dissolving L proline and potassium bromide in 1:1 molar ratio using deionized water as the solvent. The crystal parameters of the grown crystals have been evaluated by single crystal and powder XRD methods. Optical spectral studies have been carried out to find the band gap and optical constant...

We present a model and discretization that couples the Ericksen model of liquid crystals with variable degree of orientation to the Allen-Cahn equations with a mass constraint. The coupled system models liquid crystal droplets with anisotropic surface tension effects due to the liquid crystal molecular alignment. The total energy consists of the Ericksen energy, phase-field (Allen-Cahn) energy,...

We demonstrate a replica-molding method for submicron patterning of a low-index sol–gel nanoporous glass for the purpose of fabricating large-area ( 80 cm) label-free photonic crystal optical biosensors. Scanning electron micrographs show the sol–gel exhibited minimal shrinkage and good substrate adhesion and depict precise and uniform pattern transfer over the fabricated area within the limits...

Dental caries are slowly progressive and infectious disease, which result in localized dissolution and destruction of the calcified tissues. In routine clinical treatments, microleakage following with secondary caries usually occurs due to the discrepancy in physico-chemical property between filled materials and tooth. Ideal filling materials for tooth defect should be similar to the structure ...

Crystal structure, morphology, and optical properties of Tm, Er, and Yb ions doped four types of host materials [NaLnF4, Ln=Y, Lu, Gd, La] have been investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectra were used to characterize the samples. For La-based fluoride, the as synthesized microcrystals are assigned to LaF3 crystal phase. For the...

Here we present a simple physical method to prepare magnetic nanodiamonds (NDs) using high dose Fe ion-implantation. The Fe atoms are embedded into NDs through Fe ion-implantation and the crystal structure of NDs are recovered by thermal annealing. The results of TEM and Raman examinations indicated the crystal structure of the Fe implanted NDs is recovered completely. The SQUID-VSM measurement...