Bell Labs

About: Bell Labs is a based out in . It is known for research contribution in the topics: Laser & Optical fiber. The organization has 36499 authors who have published 59862 publications receiving 3190823 citations. The organization is also known as: Bell Laboratories & AT&T Bell Laboratories.

Advanced Modulation Formats for High-Capacity Optical Transport Networks

Abstract: Advanced optical modulation formats have become a key ingredient to the design of modern wavelength-division-multiplexed (WDM) optically routed networks. In this paper, we review the generation and detection of multigigabit/second intensity- and phase-modulated formats and highlight their resilience to key impairments found in optical networking, such as optical amplifier noise, chromatic dispersion, polarization-mode dispersion, WDM crosstalk, concatenated optical filtering, and fiber nonlinearity

6×56-Gb/s mode-division multiplexed transmission over 33-km few-mode fiber enabled by 6×6 MIMO equalization

Abstract: Mode-division multiplexing over 33-km few-mode fiber is investigated. It is shown that 6×6 MIMO processing can be used to almost completely compensate for crosstalk and intersymbol interference due to mode coupling in a system that transmits uncorrelated 28-GBaud QPSK signals on the six spatial and polarization modes supported by a novel few-mode fiber.

Infrared spectroscopy of Landau levels of graphene.

Abstract: We report infrared studies of the Landau level (LL) transitions in single layer graphene. Our specimens are density tunable and show in situ half-integer quantum Hall plateaus. Infrared transmission is measured in magnetic fields up to $B=18\text{ }\text{ }\mathrm{T}$ at selected LL fillings. Resonances between hole LLs and electron LLs, as well as resonances between hole and electron LLs, are resolved. Their transition energies are proportional to $\sqrt{B}$, and the deduced band velocity is $\stackrel{\texttildelow{}}{c}\ensuremath{\approx}1.1\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }\mathrm{m}/\mathrm{s}$. The lack of precise scaling between different LL transitions indicates considerable contributions of many-particle effects to the infrared transition energies.

Generating antialiased images at low sampling densities

Abstract: Ray tracing produces point samples of an image from a 3-D model Constructing an antialiased digital picture from point samples is difficult without resorting to extremely high sampling densities This paper describes a program that focuses on that problem While it is impossible to eliminate aliasing totally, it has been shown that nonuniform sampling yields aliasing that is less conspicuous to the observer An algorithm is presented for fast generation of nonuniform sampling patterns that are optimal in some sense Some regions of an image may require extra sampling to avoid strong aliasing Deciding where to do extra sampling can be guided by knowledge of how the eye perceives noise as a function of contrast and color Finally, to generate the digital picture, the image must be reconstructed from the samples and resampled at the display pixel rate The nonuniformity of the samples complicates this process, and a new nonuniform reconstruction filter is presented which solves this problem efficiently

The Examination and Analysis of Residuals

Abstract: A number of methods for examining the residuals remaining after a conventional analysis of variance or least-squares fitting have been explored during the past few years. These give information on various questions of interest, and in particular, aid in assessing the validity or appropriateness of the conventional analysis. The purpose of this paper is to make a variety of these techniques more easily available, so that they can be tried out more widely. Techniques of analysis, some graphical, some wholly numerical, and others mixed, are discussed in terms of the residuals that result from fitting row and column means to entries in a two-way array (or in several two-way arrays). Extensions to more complex situations, and some of the uses of the results of examination, are indicated.