Unambiguous state discrimination of coherent states with linear optics: Application to quantum cryptography

  • Van Enk S.

We discuss several methods for unambiguous state discrimination of N symmetric coherent states using linear optics and photodetectors. One type of measurement is shown to be optimal in the limit of small photon numbers for any N. For the special case of N = 4 this measurement can be fruitfully ...

Can a more neutral position of the forearm when operating a computer mouse reduce the pain level for VDU operators?

  • Aaras A.
  • Dainoff M.
  • Ro O.
  • Thoresen M.

A prospective epidemiological field study covering a 1-year period has been published (Int. J. Hum.-Comput. Interaction, 1999; 2001). The aim of the study was to investigate if subjects with existing musculoskeletal pain experience a reduction in pain development when using a new mouse design (Anir/Renaissance) which allows a more neutral ...

Integrated link adaptation and power control to improve error and throughput performance in broadband wireless packet networks

  • Leung K.
  • Wang L.

In this paper, we prove that the problem of maximizing data throughput by adaptive modulation and power control while meeting packet error requirements is NP-complete. A heuristic algorithm for integrated link adaptation and power control is, thus, proposed to achieve specified error rates and to improve overall throughput for real-time ...

Estimation of continuous flat fading MIMO channels

  • Cox D.
  • Huang H.
  • Lozano A.
  • Sun Q.

Multiple-input-multiple-output (MIMO) systems can provide high data rate wireless services in a rich scattering environment. In this paper, we study one of the proposals for MIMO systems, the Bell Labs Layered Space-Time (BLAST) architecture. Channel estimation using training sequences is required for coherent detection in BLAST. We apply the maximum-likelihood ...

160-Gb/s all-optical MEMS time-slot switch for OTDM and WDM application

  • Chand N.
  • Kojima K.
  • Pau S.
  • Swaminathan V.
  • Yu J.

The authors propose and successfully demonstrate a novel, simple, and low-cost concept of optical time-slot switching, i.e., switching part of one 160-Gb/s optical time-division multiplexing channel to another 160 Gb/s channel all in optical domain without any optical-electrical-optical conversion and with negligible power penalty.

Density clamping and longitudinal spatial hole burning in a gain-clamped semiconductor optical amplifier

  • Crottini A.
  • Dagens B.
  • Deveaud B.
  • Dupertuis M.
  • Emery J.
  • Kappei L.
  • Kuroda K.
  • Marti D.
  • Nomura M.
  • Salleras F.
  • Shimura T.

We have directly measured, under operating conditions, the distributions of carrier densities and temperatures in a gain-clamped semiconductor optical amplifier designed for operation at 1.55 mum. As expected, longitudinal spatial hole burning is much smaller than in conventional semiconductor optical amplifiers and the effects of gain clamping are clearly evidenced. ...

Percolative superconductivity in Mg1-xB2

  • Chen C.
  • Cheong S.
  • Cieplak M.
  • Guha S.
  • Horibe Y.
  • Hur N.
  • Kim B.
  • Sharma P.

Our results from various transport experiments on Mg1-xB2 indicate a surprising effect associated with the presence of a Mg deficiency in MgB2: the phase separation between Mg-vacancy rich and Mg-vacancy poor phases. The Mg-vacancy poor phase is superconducting, but the insulating nature of the Mg-vacancy rich phase probably originates from ...

Investigation of ZnO epilayers grown under various Zn/O ratios by plasma-assisted molecular-beam epitaxy

  • Chen Y.
  • Hong S.
  • Ko H.
  • Yao T.

We have investigated ZnO epilayers grown under various Zn/O ratios by plasma-assisted molecular-beam epitaxy. The growth conditions are elucidated by a relationship between growth rate and Zn/O ratios. Surface phase diagrams are obtained by investigation of reflection high-energy electron diffraction. Hexagonal-shaped two-dimensional islands with atomic steps measured by atomic force ...

Optical speedup at transparency of the gain recovery in semiconductor optical amplifiers

  • Dagens B.
  • Deveaud B.
  • Dupertuis M.
  • Emery J.
  • Hessler T.

Experimental demonstration of optical speedup at transparency (OSAT) has been performed on a 1 mm long semiconductor optical amplifiers (SOA). OSAT is a recently proposed scheme that decreases the recovery time of an SOA while maintaining the available gain. It is achieved by externally injecting into the SOA the beam ...

In situ stepwise surface analysis of micropatterned glass substrates in liquids using functional near-field scanning optical microscopy

  • Buettner H.
  • Garfias L.
  • Schmalenberg K.
  • Thompson D.
  • Uhrich K.

Imaging of two adsorbed proteins on micropatterned glass substrates in air and liquid was conducted using atomic force microscopy (AFM) and near-field scanning optical microscopy (NSOM). The micropatterned glass substrates were prepared in five steps and evaluated by NSOM at each processing step. The micropatterned samples consisted of alternating 10 ...

Special issue: Adaptive antennas and MIMO systems

  • Alouini M.
  • Molisch A.
  • Valenzuela R.

Trade-offs in the quantum search algorithm

  • Grover L.

Quantum search has been proved to be the best possible algorithm for the exhaustive search problem in the sense that the number of queries it requires cannot be reduced. However, the number of nonquery operations, and thus the total number of operations, can be reduced. The number of nonquery unitary ...

A simplified EM algorithm for detection of CPM signals in a fading multipath channel

  • Kobayashi H.
  • Zeger L.

Application of the EM (Expectation-Maximization) algorithm to sequence estimation in an unknown channel can in principle produce MLSE (maximum likelihood sequence estimates) that are not dependent on a particular channel estimate. The Expectation step of this algorithm cannot be directly performed for continuous phase modulated (CPM) signals transmitted in a ...

Electroplating and properties of SnBi and SnCu for lead-free finishes

  • Abys J.
  • Fan C.
  • Khaselev O.
  • Vysotskaya A.
  • Zavarine I.
  • Zhang Y.

Tin alloys such as Sn-0.7% Cu and Sn-2% Bi were identified as viable alternatives to tin-lead finishes. Electroplating of these alloys is challenging because of the great difference in reduction Potentials of the individual elements and the usual problems associated with strong immersion deposition and poor alloy control. To overcome ...

Stopping light on a defect (vol 19, pg 1635, 2002)

  • Goodman R.
  • Slusher R.
  • Weinstein M.

Gain-bandwidth limitations of microwave transistor

  • Gunes F.
  • Tepe C.

This work enables one to obtain the potential gain (G(T)) characteristics with the associated source (Z(S)) and load (Z(L)) termination functions, depending upon the input mismatching (V-i), noise (F), and the device operation parameters, which are the configuration type (CT), bias conditions (V-DS, I-DS), and operation frequency (f). All these ...

Deterministic channel modeling and performance simulation of microcellular wide-band communication systems

  • Clerckx B.
  • Oestges C.
  • Raynaud L.
  • Vanhoenacker-Janvier D.

To evaluate the performance of future microcellular IMT-2000 modems, simple physical models are required, so that a number of system characteristics, such as the signal bandwidth, the antenna beamwidth, or the base station height can be accounted for at a limited computational cost. This paper describes a deterministic three-dimensional electromagnetic ...