Makiko Hisatomi

Zoned microstructure fiber for low-dispersion waveguiding and coupling to photonic crystals

We describe a zoned microstructure fiber that exhibits low dispersion and virtually zero spherical aberration because of its optimized piecewise Gaussian index profile. We present results of a nine-zone design that has an average refractive index of 2.3, a refractive-index contrast of 0.1, a first zone radius of 1.67 microm, and a maximum core radius of 5 microm. It has an in-fiber focal length of 8.88 microm and can focus light to a spot size of radius 315 nm, facilitating efficient coupling between single-mode fiber and photonic crystals.

Application of Service Delivery Platform for Supply Chain Management

This paper examines how utilization of Service Delivery Platform (SDP) technology can potentially address some of the key issues facing the existing retail supply chain management (SCM). Existing SCM issues are identified and an analysis of the key functionality requirements for SDPs is described. Meeting these requirements ensures that SDP can provide a collaborative platform for a supply chain with improved end-to-end visibility. Thus the supply chain can better respond to market changes, particularly advantageous in todays demand-driven market.

Binary multi-zoned microstructured fiber: a comparative dispersion analysis of radially chirped Bragg fiber

We analyze binary radially chirped Bragg fiber (RCBF) having the geometry of a binary multi-zoned microstructured fiber (MSF). As it is, in effect, a longitudinally extended binary Fresnel lens, we find that it propagates light via periodic refocusing into the center of the fiber. Zoning produces unusual dispersion properties, so we present a comparative analysis with other zoned MSF geometries, such as single-mode fiber (SMF; effectively consisting of only one zone) and conventional (unchirped) Bragg fiber. We perform an eigenmode expansion of Maxwells equations for the three fiber geometries and find that the SMF and Bragg fiber have similar modal dispersion, with monotonic waveguide dispersion for all modes at high frequencies, whereas RCBF exhibits oscillatory behavior, with modal dispersion varying between positive and negative values as the frequency increases. This demonstrates that zoning introduces flexibility in the engineering of desired waveguide-dispersion characteristics.

Comparison of zoned microstructure fiber geometries for low-dispersion waveguiding

This paper presents a comprehensive analysis of zoning in microstructure fiber (MSF) in which parabolic and Gaussian graded-index (GRIN) refractive-index profiles are compared in both continuous and zoned geometries. Ray trajectories were calculated using Fermats principle of least time and the paraxial approximation. Optimization of the zoned MSF refractive-index profile revealed that a piecewise Gaussian refractive-index profile exhibits aberration of just 10-nm on-axis focal variation, compared with 40 nm in the zoned parabolic case. In addition, a quarter-period length of the Gaussian-zoned MSF has a 630-nm theoretical spot-size, thus offering efficient coupling between standard single-mode fiber and photonic-crystal devices. A preliminary analysis of a binary radially chirped Bragg fiber geometry is performed using an eigenmode expansion of Maxwells equations. Its simpler geometry offers fabrication advantages, but its spot size is closer to 1.2 /spl mu/m due to its 41-/spl mu/m quarter-period focal length, and it suffers greater waveguide dispersion compared with the optimized zoned GRIN MSF geometry presented here.

Low refractive-index-contrast Fresnel-microstructure fibre for coupling between SMF and photonic crystals

A method is described to efficiently couple light between single-mode fibre (SMF) and photonic crystals (PhCs) using a novel Fresnel-zone (FZ) MSF lens. In this study, the proposed FZ-MSF lens focuses light in a similar way to a graded-index (GRIN) rod lens, but instead of having a continuous parabolic refractive index variation, the MSF employs longitudinal FZs to focus light from SMF down to PhC dimensions, and vice-versa. Details on the equations describing the trajectory of a light ray in a medium with spatially-varying refractive index is also discussed.

Hollow-core radially-chirped Bragg fiber for quasi-metallic photonic bandgap light confinement

We analyze hollow-core radially-chirped Bragg fiber which propagates light via oscillatory modal evolution and lens relay refocusing with 55 mum full-period. Our design shows both photonic bandgap light confinement in an aperiodic geometry, and quasi-metallic waveguide properties

Waveguiding of orbital angular momentum light using chiral-selectivity azimuthally graded index fibre

We describe a novel chiral azimuthally graded-index fibre which guides only one handedness of orbital angular momentum light. Such fibre may find application in physical layer cryptography using photons with high order orbital angular momentum.

Singular optical fibre featuring refractive index dislocation for chiral waveguiding of high orbital angular momentum light

We describe a novel chiral azimuthally graded-index fibre which guides only one handedness of high orbital angular momentum light. Featuring an index dislocation, our singular optical fibre may find applications in cryptography or optical tweezers.