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...

For the scalar wave equation in periodic structures, we establish rigorously the emergence of a spectral bandgap as a frequency interval of exponentially small transmission of energy through a slab of the crystal when the thickness of the slab tends to infinity. We extend the result to slabs that contain a planar defect for frequencies that do not coincide with guided mode frequencies for the d...

ZnO thin films of porous structure with strong c-axis orientation were deposited on n-type silicon substrate by pulsed laser ablation of ZnO target in low O2 pressure (around 0.03 mbar) and at 600C substrate temperature. We attribute the formation of nanopores and the crater-like formation to the high kinetic energy of the ablated particles. Photoluminescence spectra show the near band edge emi...

The local dispersion relation of a photonic crystal waveguide is directly determined by phase-sensitive near-field microscopy. We readily demonstrate the propagation of Bloch waves by probing the band diagram also beyond the first Brillouin zone. Both TE and TM polarized modes were distinguished in the experimental band diagram. Only the TE polarized defect mode has a distinctive Bloch wave cha...

Between January 1976 and July 1983, 217 patients with atrial septal defect underwent surgical repair at Children's Hospital. Thirty with a primum atrial septal defect and 26 who underwent cardiac catheterization elsewhere before being seen were excluded from analysis. Of the 161 remaining patients, 52 (31%) underwent preoperative cardiac catheterization, 38 because the physical examination was ...

Building upon the results of recent work [1], we use momentum space design rules to investigate high quality factor (Q) optical cavities in standard and compressed hexagonal lattice photonic crystal (PC) slab waveguides. Beginning with the standard hexagonal lattice, the results of a symmetry analysis are used to determine a cavity geometry that produces a mode whose symmetry immediately leads ...

We present an exact theory for modelling the modes of two-dimensional photonic crystals with a truly infinite cladding. It builds on our previous implementation of the fictitious source superposition method for simple point defects that is based on three key ideas: the use of fictitious sources to modify response fields so defects can be introduced; the representation of the defect mode as a su...

We study the formation and evolution of localized geometrical defects in an indented cylindrical elastic shell using a combination of experiment and numerical simulation. We find that as a symmetric localized indentation on a semicylindrical shell increases, there is a transition from a global mode of deformation to a localized one which leads to the condensation of curvature along a symmetric ...

M-mode echocardiographic features are presented in four patients with membranous ventricular septal defect. The most consistent echo findings in all the patients were the presence of fuzzy, fluttering echoes of the tricuspid valve during systole. More careful echocardiographic evaluation of the tricuspid valve in ventricular septal defect is therefore recommended.