We describe a multipole formulation that can be used for high-accuracy calculations of the full complex propagation constant of a microstructured optical fiber with a finite number of holes. We show how the imaginary part of the microstructure, which describes confinement losses not associated with absorption, varies with hole size, the number of rings of… (More)
We numerically show that the zero-dispersion wavelength of As<sub>2</sub>S<sub>3</sub> used in a waveguide can be shifted sufficiently to allow broadband amplification and wavelength conversion via four-wave mixing at telecom wavelengths. The device implications are investigated.
We consider mode coupling in multimode optical fibers using either two Bragg gratings or a Bragg grating and a long-period grating. We show that the magnitude of the band edge curvature can be controlled leading to a flat, quartic band-edge or to two band edges at distinct, nonequivalent k-values, allowing precise control of slow light propagation.
We demonstrate that the spatial profiles of both propagating and evanescent Bloch modes in a periodic structure can be extracted from a single measurement of an electric field at the specified optical wavelength. We develop a systematic extraction procedure by extending the concepts of high-resolution spectral methods previously developed for temporal data… (More)
We experimentally study the fields close to an interface between two photonic crystal waveguides that have different dispersion properties. After the transition from a waveguide in which the group velocity of light is v(g) ~ c/10 to a waveguide in which it is v(g) ~ c/100, we observe a gradual increase in the field intensity and the lateral spreading of the… (More)
We consider the evolution of defect modes created in complete band gaps of 2D photonic crystals by altering the dielectric constant in some region. We derive a simple exponential law which links the frequency difference between the defect mode and the band edge to the dielectric constant change.
We examine the conditions for dynamic localization of electrons in a periodic potential due to an applied ac electric field. Using a general one-band model, we establish the surprising result that only electric fields that are discontinuous at all changes of sign can lead to exact dynamic localization. We also develop a general procedure for constructing ac… (More)
We present an exact method for modelling modes of general defects with infinite cladding. It handles the pathological case of highly extended modes and establishes the fundamental mode of a conventional PCF has no cut-off.
Degenerate band edges (DBEs) of a photonic bandgap have the form (ω-ω(D)) ∝k(2m) for integers m>1, with ω(D) the frequency at the band edge. We show theoretically that DBEs lead to efficient coupling into slow-light modes without a transition region, and that the field strength in the slow mode can far exceed that in the incoming medium. A method is… (More)
We demonstrate that cavities with Q∼10<sup>7</sup> can be designed in defect-free photonic crystals made of photosensitive material (chalcogenide). Since the high-Q mode can originate from an air-band, these cavities are ideal candidates for sensing applications.