The numerical dispersion relation that governs the propagation of fields in a finite-difference time-domain (FDTD) grid was derived several years ago. In this paper a different interpretation is given for the governing equation. It is shown that the dispersion relation predicts fasterthan-light propagation for coarsely resolved fields. Additionally, some spectral components that were previously...

We report time-of-flight experiments on photonic-crystal waveguide structures using optical Kerr gating of a femtosecond white-light supercontinuum. These photonic-crystal structures, based on engineered silicon-nitride slab waveguides, possess broadband low-loss guiding properties, allowing the group velocity dispersion of optical pulses to be directly tracked as a function of wavelength. This...

OBJECTIVE To test the hypothesis that the retinal pigment epithelial/photoreceptor complex is affected in patients with pigment dispersion syndrome and/or in patients with pigmentary glaucoma. METHODS Electro-oculograms were recorded from patients with pigment dispersion syndrome, pigmentary glaucoma, ocular hypertension, and primary open-angle glaucoma and from control subjects. Electro-ocul...

We examine the effects on the Fundamental Plane (FP) of structural departures from an R galaxy light profile. We also explore the use of spatial (i.e. volumetric) as well as projected galaxy parameters. We fit the Sersic R law to the V-band light profiles of 26 E/S0 Virgo galaxies, where n is a shape parameter that allows for structural differences amongst the profiles. The galaxy light profile...

Nanobiocomposites of poly(lactic acid) (PLA) with 3–5 wt% organically modified montmorillonite (OMMT) were prepared by melt compounding in two different mixers, miniature twin-screw extruder and internal batch mixer, leading to different degrees of dispersion. The progress of dispersion was characterized by melt rheology coupled with light attenuation. Processed PLA/OMMT samples showed percolat...

We demonstrate third-harmonic generation (THG) in a dispersion-engineered slow-light photonic crystal waveguide fabricated in AMTIR-1 chalcogenide glass. Owing to the relatively low loss and low dispersion in the slow-light (c/30) regime, combined with the high nonlinear figure of merit of the material (∼2), we obtain a relatively large conversion efficiency (1.4×10(-8)/W(2)), which is 30× high...

We describe a resonator-based optical gyroscope whose sensitivity for measuring absolute rotation is enhanced via use of the anomalous dispersion characteristic of superluminal light propagation. The enhancement is given by the inverse of the group index, saturating to a bound determined by the group velocity dispersion. We also show how the offsetting effect of the concomitant broadening of th...

We present a far-field optical technique allowing measurements of the dispersion relation of electromagnetic fields propagating under the light cone in photonic nanostructures. It relies on the use of a one-dimensional grating to probe the evanescent tail of the guided field in combination with a high-numerical-aperture Fourierspace imaging setup. A high-resolution spectroscopy of the far-field...

Spectral dispersion of light on a finite-size surface plasmon polaritonic (SPP) crystal has been studied. The angular wavelength separation of one or more orders of magnitude higher than in other state-of-the-art wavelength-splitting devices available to date has been demonstrated. The two-stage process is responsible for the dispersion value, which involves conversion of the incident light int...

In this paper we discuss the evidence for a period-luminosity (PL) relation and periodluminosity-colour (PLC) at maximum light for Mira variables. We confirm the existence of such relations in the J, H and K bands, and also based on bolometric magnitudes, for oxygen-rich (O) and carbon-rich (C) Miras in the LMC. We demonstrate that in the J and H bands the maximum light PL relations have a sign...