Large Synoptic Survey Telescope: Overview

  • Tyson J.

A large wide-field telescope and camera with optical throughput over 200 m sup 2 deg sup 2 -- a factor of 50 beyond what we currently have -- would enable the detection of faint moving or bursting optical objects: from Earth threatening asteroids to energetic events at the edge of ...

GaN-based Intersubband Structures and Mid-Infrared Cascade Lasers with Heterogeneous Cascades

  • Capasso F.
  • Cho A.
  • Colombelli R.
  • Gmachl C.
  • Heber J.
  • Ng H.
  • Sivco D.
  • Soibel A.

We review two recent developments in the field of quantum cascade lasers. First, early studies of the GaN/AlGaN material system demonstrate the suitability of the latter for the communications wavelength renge. Intersubband absorption measurements at wavelengths as short as lambda >= 1.35 mum are reprorted in multiple coupled quantum wells. ...

Vapor Sensing with alpha, omega-Dihexylquarterthiophene Field-Effect Transistors: The Role of Grain Boundaries

  • A. Dodabalapur
  • A. Gelperin
  • Katz H.
  • Lovinger A.
  • T. Someya

We have investigated the channel-length dependence of responses to a vapor analyte with a series of alpha, omega-dihexylquarterthiophene (DHalpha4T) field-effect transistors (FETs). Single-crystalline DHalpha4T devices deposited by vacuum sublimation at substrate temperatures of 70 degC are compared with polycrystalline DHalpha4T films deposited at room temperature. By changing the length of ...

Correlation Between Oligothiophene Thin Film Transistor Morphology and Vapor Responses

  • A. Dodabalapur
  • A. Gelperin
  • B. Crone
  • Katz H.
  • L. Torsi
  • Lovinger A.
  • T. Someya

Oligothiophene thin film transistors have recently been shown to respond to organic vapors. suggesting possible applicability in the field of olfactory sensor arrays. Here we present a study of the correlation between the morphological structure of the active semiconductor thin film and response to the vapor. The study was carried ...

A Microscope for Imaging, Spectroscopy, and Lithography at the Nanometer Scale: Combination ofa Two-Photon Laser Scanning Microscope and an Atomic Force Microscope

  • Chaban E.
  • F.F. Schey
  • Hsu J.
  • Matthews M.

We designed and built a unique instrument that combines a two-photon laser scanning microscope (LSM) with an inverted atomic force microscope (AFM). Local photoluminescence (PL) spectroscopy and three-dimensional lithography are demonstrated using the two-photon LSM. High spatial resolution topographic images from the AFM can be recorded simultaneously with the PL ...

Submicron AlGaN/GaN HEMTs with very high drain current density grown by plasma Assisted MBE on 6H-SiC

  • Manfra M.
  • S. Chakraborty
  • Tennant D.
  • Weimann N.

High Electron Mobility Transistors (HEMTs) were fabricated from AlGaN/GaN layers grown by plasma-assisted Molecular Beam Epitaxy on semi-insulating 6H-SiC substrates. This is the first report of high-power submicron AlGaN/GaN HEMTs grown by plasma-assisted MBE on semi-insulating 6H-SiC substrates, and the highest drain current density in any AlGaN/GaN HEMT structure delivering ...

Evidence of Landau Levels and Interactions in Low-Lying Excitations of Composite Fermions at 1/3 <= v <= 2/5

  • Dennis B.
  • I. Dujovne
  • M. Kang
  • Pfeiffer L.
  • Pinczuk A.
  • West K.

Excitation modes in the range 2/5 >= v >= 1/3 of the fractional quantum Hall regime are observed by resonant inelastic light scattering. Spectra of spin reversed excitations suggest a structure of lowest spin-split Landau levels of composite fermions that is similar to that of electrons. Spin-flip energies determined from ...

Circular and deformed microdisks quantum cascade lasers with surface plasmon waveguides at wavelengths from 19 micron

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

We report the fabrication and characterization of microdisk Quantum Cascade (QC) lasers with surface plasmon waveguides. Previously realized microdisk QC lasers employed fully dielectric waveguides, and therefore did not need the top contact to cover all the surface of the disk. Since the metal contact is however an integral part ...

Inelastic Light-Scattering and Photoluminescence from Extremely High-Mobility Very Dilute Two-Dimensional Hole Gases

  • Dennis B.
  • Pfeiffer L.
  • Pinczuk A.
  • Plaut A.
  • West K.

We have observed charged excitons by optical emission and intersubband transitions by inelastic light-scattering in two-dimensional very dilute hole gases with As-grown hole densities down to below p = 6.5x10 sup 9 cm sup -2. The hole mobility reaches 2.1x10 sup 6 cm sup 2/Vs at 0.3 Kelvin.

DNA unzipped under a constant force exhibits multiple metastable intermediates

  • C. Bouzig
  • C. Danilowicz
  • D.R. Nelson
  • Lubensky D.
  • M. Prentiss
  • V.W. Coljee

Single molecule studies, at a constant force, of the separation of double stranded DNA (dsDNA) into two separated single strands (ssDNA) may provide information relevant to the dynamics of DNA replication. Theory predicts that the unzipped length as a function of time is characterized by jumps during which the strands ...

Quantum Cascade Lasers with Heterogeneous, Stacked Cascades: Sum-Frequency and Second Harmonic Generation

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

Quantum cascade (QC) lasers have recently been demonstrated with stacked, interdigitated or collaborative cascades. Different active regions, in all cases of the "three-well vertical transition" type and designed at different emission wavelengths, were stacked -- with matching injector regions -- and inserted into one waveguide core. This approach is attractive ...

GaInAs/InP Quantum Cascade Electroluminescent Devices

  • Capasso F.
  • Chen J.
  • Cho A.
  • Gmachl C.
  • Peabody M.
  • Sivco D.
  • Troccoli M.

Quantum Cascade (QC) lasers are based on inter-subband transitions in the conduction band. This characteristic gives the flexibility to design the active region specifically to meet the user requirements, almost independently of the material chosen for its realization. So far, laser action has been reported in a great number of ...

Mid-IR Electroluminescence in Quantum Cascade Structures with GaInAs/InP Active Region

  • Capasso F.
  • Chen J.
  • Cho A.
  • Gmachl C.
  • Peabody M.
  • Sivco D.
  • Troccoli M.

Quantum Cascade (QC) lasers are based on inter-subband transitions in the conduction band. This characteristic gives the flexibility to design the active region specifically to meet the user requirements, almost independently of the material chosen for its realization. So far, laser action has been reported in a number of different ...

40-Gbit/s RZ-Transmission over 1200 km using an Integrated Electroabsorption-Modulated Laser

  • H. Feng
  • Raybon G.
  • Su Y.
  • T. Makino
  • Wei X.

We report pseudo-linear transmission of a single-channel 40-Gb/s signal over non-zero dispersion-shifted fiber (NZDSF) using an integrated electroabsorption-modulated laser (EML) in the transmitter for data modulation. RZ-format transmission over 1200-km is achieved with a measured Q of 15.6 dB or bit-error-rate of 10 sup -9.

Frequency Stabilization of Quantum Cascade Lasers using Optical Cavities

  • B.D. Cannon
  • Capasso F.
  • Cho A.
  • Gmachl C.
  • M.S. Taubman
  • R.M. Williams
  • Sivco D.
  • T.L. Myers

We report a heterodyne beat with a line width of 5.6 += 0.6 Hz between two cavity-stabilized quantum cascade lasers operating at 8.5 micron. We also present a technique for this measurement that avoids the need for extreme isolation of the optical cavities from the environment; that of employing a ...

The Deep Lens Survey

  • A. Clocchiatti
  • A. Gonzalez
  • Becker A.
  • C. Stubbs
  • D. Loomba
  • D. Spergel
  • D. Zaritsky
  • G. Bernstein
  • G. Squires
  • G. Wilson
  • I.P. Dell'Antonio
  • J. Cohen
  • J. Hennawi
  • M. Hamuy
  • Margoniner V.
  • P. Boeshaar
  • R. Guhathakurta
  • S. Selijak
  • Tyson J.
  • W. Hu
  • Wittman D.

The Deep Lens Survey (DLS) is a deep BV Rz' imaging survey of seven 2 deg x 2 deg degree fields, with all data to be made public. The primary scientific driver is weak gravitational lensing, but the survey is also designed to enable a wide array of other astrophysical ...

Weak Lensing Discovery and Tomography of a Cluster at Z = 0.68

  • I.P. Dell'Antonio
  • J.G. Cohen
  • Margoniner V.
  • Tyson J.
  • Wittman D.

We report the discovery, spectrographic confirmation, and weak lensing tomography of a massive cluster of galaxies at z = 0.68. The first shear-selected cluster from the Deep Lens Survey, a deep optical imaging survey of 28 deg sup 2, it dominates the weak lensing mass map of its 40' field. ...

Imaging Mass in Three Dimensions

  • Becker A.
  • I.P. Dell'Antonio
  • J.G. Cohen
  • Margoniner V.
  • Tyson J.
  • Wittman D.

We explore a possible "killer app" for the LSST and similar surveys: imaging mass in three dimensions. We describe its scientific importance, practical technique for realizing it, the current state of the art and how it might scale to the LSST.

OSNR Margin Assessment for Optical Transmissions in the Nonlinear Regime with Forward Error Correction

  • Chandrasekhar S.
  • Gnauck A.
  • Liu X.
  • Wei X.

We study numerically and experimentally the OSNR margin of high-speed optical transmission systems in the nonlinear regime at FEC thresholds. It is found that the OSNR margin can be significatnly larger than the Q margin, in contrast to ideal linear case. As a result, the FEC coding gains for transmissions ...

Efficient Authentication and Key Distribution in Wireless IP Networks

  • Buddhikot M.
  • Garay J.
  • Miller S.
  • Patel S.
  • Salgarelli L.

In this paper, we first describe a simple network model that accounts for heterogeneity in network service providers, and put forward the requirements that any authentication and key exchange protocol that operates in such model has to satisfy, in terms of network efficiency, security and fraud prevention. We then introduce ...