Point defects, dislocations, grain boundaries and interfaces are always involved in ceramic microstructures play important roles for physical chemical properties of ceramics. Currently, proper control these crystal defects is inevitable to tailor materials with superior properties. This article reviews recent research projects on distinct phenomena ceramics due defects. In particular, we would ...

Defects in the atomic structure of crystalline materials may spawn electronic bound states, known as \emph{defect states}, which decay rapidly away from defect. Simplified models defect states typically assume is surrounded on all sides by an infinite perfectly material. In reality surrounding must be finite, and certain contexts can small enough that edge effects are significant. this work we ...

Localized defect regions within two-dimensional photonic crystal slab waveguides are an attractive method of forming high-quality factor optical resonators with wavelength-scale modal volumes. Using simple symmetry bases, and the tools of group theory, we develop an approximate description of the resonant modes of different photonic crystal defect cavities. Comparison to numerical simulations a...

A scanning near-field optical microscopy study is undertaken on photonic crystal tapers. These tapers are used to couple a 3 microm wide multimode dielectric waveguide to a single-line defect monomode photonic crystal waveguide. Two kinds of taper, with or without a localized defect, are compared. Higher transmission efficiency is obtained when a defect is utilized. The near-field study at 1550...

We proposed an effective index perturbation method to investigate the intrinsic characteristics of three-dimensional photonic-crystal-slab based microcavity with two-dimensional numerical simulation tools such as two-dimensional finite-difference time-domain (2D-FDTD) and plane-wave expansion (2D-PWE) techniques, for reduced computational requirements and fast design feedback. Less than 2% comp...

The control of lateral mode operation using a photonic crystal in a vertical-cavity surface-emitting laser ~VCSEL! is analyzed and confirmed experimentally. By controlling design parameters of the photonic crystal pattern, we have produced photonic crystal VCSELs that operate in higher order defect modes in addition to the fundamental defect mode. The transverse modal behavior is consistent wit...

The aim of this work is the microscopic study of the dynamics of the healing of the defect of compact bone tissue after the implantation into its cavity of osteoplastic material «easy-graft CRYSTAL». The experiment was conducted on 24 Wistar rats. In the middle third of the femoral shaft of rats there was reproduced perforated defect in the diameter of 2.5 mm to the medullary canal, which was f...

The properties of photonic crystal (PC) filters in one-dimensional photonic crystal (1D PC) containing a defect layer are studied theoretically using the transfer matrix method. The effect of thickness of defect layers is studied. It is shown that one defect mode and two defect modes appear inside the forbidden band gaps in its reflection spectra. By changing the thickness of the defect layer, ...

Waveguides with low confinement loss, low chromatic dispersion, and low nonlinear effects are used in optical communication systems. Optical fibers can also be employed in such systems. Besides optical fibers, photonic crystal fibers are also highly suitable transmission media for optical communication systems. In this paper, we introduce two new designs of index-guiding photonic crystal fiber ...