Voronoi Diagrams and Delaunay Triangulations

  • Fortune S.

The Voronoi diagram of a set of sites partitions space into regions, one per site; the region for a site s consists of all points closer to s than to any other site. The dual of the Voronoi diagram, the Delaunay triangulation, is the unique triangulation such that the circumsphere ...

Minimal group refractive index dispersion and gain evolution in ultra-broad-band quantum cascade lasers

  • Capasso F.
  • Cho A.
  • Colombelli R.
  • Gmachl C.
  • Sivco D.
  • Soibel A.

Quantum cascade (QC) lasers [1] are based on optical intersubband transitions between quantized states in the conduction band of multiple coupled quantum wells. Four distinct characteristics contribute to the uniqueness of the QC-laser. First, the peak wavelength of the active region can be chosen freely over a very wide range ...

Tunable Microfluidic Optical Fiber Devices Based On Electrowetting Pumps And Plastic Microchannels

  • Baldwin K.
  • Cattaneo F.
  • Hsieh J.
  • Mach P.
  • Rogers J.
  • T. Krupenkine
  • Yang S.

This paper introduces a class of tunable microfluidic fiber devices that uses molded plastic microchannels and electrowetting pumps. It demonstrates the application of this type of system to dynamically adjustable narrow band and wide band all-fiber filters. Compact size, low cost fabrication procedures, low power (<1 mW) consumption, non-mechanical operation ...

Scheduling Over a Time-Varying User-Dependent Channel with Applications to High Speed Wireless Data

  • Andrews D.
  • Zhang Y.

In a wireless network, a basestation transmits data to mobiles at time-varying, mobile-dependent rates due to the ever changing nature of the communication channels. In this paper we consider a wireless system in which the channel conditions and data arrival processes are governed by an adversary. We first consider a ...

Scheduling a Multi-Class Queue with Many Exponential Servers: Asymptotic Optimality in Heavy-Traffic

  • A. Mandelbaum
  • R. Atar
  • Reiman M.

We consider the problem of scheduling a queueing system in which many statistically identical servers cater to several classes of impatient customers. Service times and impatience clocks are exponential while arrival processes are renewal. Our cost is an expected cumulative discounted function, linear or non-linear, of appropriately normalized performance measures.

Yang-Lee Singularity of Two Dimensional Ising and Potts Models

  • Mccabe J.
  • T. Wydro

This presentation reviews numerical studies of Yang-Lee singularities in 2D spin models. The studies focus on finite-size scaling behavior of quantum spin chains and how that behavior can be used to obtain information on Yang-Lee singularities of associated 2D spin models. The studies obtain values for Fisher's sigma exponent and ...

Wide-Sense Nonblocking WDM Cross-Connects

  • A. Rasala
  • Haxell P.
  • Wilfong G.
  • Winkler P.

We consider the problem of minimizing the number of wavelength interchangers in the design of wide-sense nonblocking cross-connects for wavelength division multiplexed (WDM) optical networks. The problem is modeled as a graph theoretic problem that we call dynamic edge coloring. In dynamic edge coloring the nodes of a graph are ...

Dirty Paper Coding: Peturbing Off the Infinite Dimensional Lattice Limit

  • Diaz A.
  • Foschini G.

Motivated by its potential role in providing more efficient downlink signalling, we focus here on so called Dirty Paper Coding (DPC). DPC can immunize a link against interference when the erstwhile interferer is launched from the same transmit site. This promotes reuse of space/spectral communication resources even at the same ...

Selective Transparency in Resilient Optical Networks

  • Giles R.
  • Kumaran K.
  • Mitra D.
  • Nuzman C.
  • Saniee I.

Core optical networks can benefit from lower costs and increased speed by reducing O-E-O conversions through use of ultra long reach optical transport, and bit-rate and wavelength transparent cross-connects. While pure optical transparency avoids the high cost of deploying optical termination units (OTUs) for each wavelength channel, it incurs new ...

Experimental Investigation of the Performance Limitation of DPSK Systems Due to Nonlinear Phase Noise

  • Gnauck A.
  • Kim H.

It is known that amplitude fluctuations caused by amplified spontaneous emission noise can be converted into phase noise by Kerr nonlinearity, and this nonlinear phase noise can limit the performance of phase-shift-keying transmission systems. In this paper, we experimentally observe and study the performance degradation of differential-phase-shift-keying transmission systems due ...

Monitoring Optical Network Performance Degradation Due to Amplifier Noise

  • Kilper D.
  • Weingartner W.

The relationship between optical performance as monitored within a network and the end terminal optical signal to noise ratio (OSNR) and bit error rate (BER) is measured for the case of performance degradation due to amplified spontaneous emission noise. Measurements on 10 Gb/s signals reveal that performance monitoring sensitivity to ...

Emergence of Neural Integration in the Head-Direction System by Visual Supervision

  • Hahnloser R.

Head-direction (HD) cells in subcortical areas of the mammalian brain are tuned to a particular head direction in space; a population of such neurons forms a neural compass that is useful for spatial navigation. The development of neural circuits constituting the head-direction system is poorly understood. Inspired by electrophysiological experiments ...

Recent Progress in GaN-Based Superlattices for Near-Infrared Intersubband Transitions

  • Cho A.
  • Gmachl C.
  • Heber J.
  • Hsu J.
  • Ng H.
  • S.N.G. Chu

A review of the recent progress in intersubband transitions in GaN-based superlattice structures grown by plasma-assisted molecular beam epitaxy (MBE) is presented. Careful control of the growth parameters resulted in reduced threading dislocation density as well as optimized interfaces for the superlattices. Intersubband absorption has been observed from a variety ...

Base Station Assignment and Power Control Algorithms for Data Users in a Wireless Multiaccess Framework

  • A. Ganti
  • Haner M.
  • Klein T.

This paper considers the problem of assigning mobile data to base stations and modulating their transmit powers according to their respective channel gains in order to maximize the total system throughput. We consider two scenarios of time-invariant and time-varying channel behaviors. We show that the problem is NP complete and ...

Sync-MS: Synchronized Messaging Service for Real-Time Multi-Player Distributed Games

  • Guo K.
  • Lin Y.
  • Paul S.

In this paper we introduce the concept of "fair order" of player action messages, and propose a game-independent, network-based service that balances the trade-off between response time and fair order of player actions. The proposed service, called Sync-MS, uses two mechanisms, Sync-out and Sync-in, to address two desired features of ...

All-Optical 2R-Regeneration of 40-Gb/s Signal Impaired by Intra-Channel Four-Wave Mixing

  • Essiambre R.
  • Raybon G.
  • Su Y.
  • T. Her

We experimentally investigate the ability of an all-optical 2R-regenerator to suppress impairments caused by intra-channel four-wave mixing and intra-channel cross-phase modulation, which are the two dominant nonlinear effects in 40-Gb/s pseudo-linear transmission systems. The 2R-regenerator suppoesses amplitude fluctuations induced by intra-channel four-wave mixing in 80-km transmission over standard single-mode fiber, ...

Automatic Colorless Tunable Dispersion Compensator Integrated with a Tunable Noise Filter

  • Bernasconi P.
  • Buhl L.
  • Chandrasekhar S.
  • Doerr C.
  • R. Pafchek
  • Stulz L.

We integrate an improved colorless thermooptic-lens-based tunable dispersion compensator (tuning range of += 160 ps/mn) with a tunable amplified spontaneous emission filter on a single silica waveguide chip. We demonstrate fast automatic adjustment of the compensator.

NxN Arrayed Waveguide Gratings with Improved Frequency Accuracy

  • Bernasconi P.
  • Cappuzzo M.
  • Chen E.
  • Gomez L.
  • Laskowski E.
  • Stulz L.
  • Wong-Foy A.

The limitation imposed by the frequency standards on the performance of NxN Arrayed Waveguide Gratings (AWGs) are reviewed for different device's layouts. An improved design that allows for an enhanced frequency accuracy of the transmission response of the device is presented and experimentally verified. The maximum deviation from the frequency ...

Scheduling Reserved Traffic in Input-Queued Switches: New Delay Bounds via Probabilistic Techniques

  • Andrews D.
  • M. Vojnovic

We consider the problem of providing delay bounds to reserved traffic in high-speed input-queued switches. We assume that the matrix of bandwidth demands is known and we use the now standard approach of decomposing this matrix into a convex combination of permutation matrices. Our problem therefore reduces to the problem ...

Homogenization Expansion for Resonances of Microstructured Photonic Waveguides

  • Golowich S.
  • Weinstein M.

We develop a homogenization expansion approach to photonic waveguides, whose transverse structures are N-fold rotationally symmetric. Examples include microstructured, or "holey," optical fibers with air holes arranged in one or more concentric rings. Our methods apply to structures, where the microfeatures have arbitrary geometry. We carry out a homogenization/perturbation expansion ...