Near-Field Microscope Probe for Far Infrared Time Domain Measurements

  • Brener I.
  • Bruce A.
  • Federici J.
  • Mitrofanov O.
  • Ruel R.
  • Wanke W.
  • Wynn J.

A near-field probe fabrication technique for far infrared frequencies based on photoconducting antennas is developed. Subwavelength- size field source is accomplished by means of an aperture and protruding high refractive index tip. The near-field probe is tested using free space traveling electrmagnetic pulses with a broadband spectrum in the range ...

Transition Temperature and Magnetoresistance in Double-Exchange Compounds With Moderate Disorder

  • Narimanov E.
  • Varma C.

We develop a variational mean-field theory of the ferromagnetic transition in compounds like Lanthanum-Manganite within the framework of the Double-Exchange Model supplemented by modest disorder. We obtain analytical expressions for the transition temperature, its variation with the valence electron-density and its decrease with disorder. We derive an expression for the ...

Estimates of the Distance Distribution of Codes and Designs

  • Ashikhmin A.
  • Barg A.
  • Litsyn S.

We consider the problem of bounding the distance distribution for unrestricted block codes with known distance and/or dual distance. By an application of the polynomial method we derive several upper and lower bounds both for finite length and for sequences of codes of growing length. We provide a general framework ...

80 nm Spectrally-Flattened, High Power Erbium Amplified Spontaneous Emission Fiber Source

  • Ales G.
  • Espindola R.
  • Park J.
  • Strasser T.

We report a novel two-stage spectrally-flattened, high output power erbium amplified spontaneous emission (ASE) fiber source pumped using a single laser diode pump. The source has a spectrally flattened bandwidth of 80 nm with an output power of +13 dBm (20 mW). We used long period gratings to flattened the ...

Femtosecond Dynamics and Absorbance of Self-Organized InAs Quantum Dots Emitting Near 1.3microns at Room Temperature

  • Birkedal D.
  • Bloch J.
  • Pfeiffer L.
  • Shah J.
  • West K.

High-sensitivity, femtosecond differential transmission measurements on self-organized InAs quantum dots at room temperature allow us to determine the dynamics of resonantly excited electron-hole pairs, as well as the absorbance (alpha sub 0 d) of quantum dots. The room temperature differential transmission signal decreases with a time constant of 65 ps, ...

Time-Division Multiplexing of Pump Wavelengths to Achieve Ultra Broadband, Flat, Backward-Pumped Raman Gain

  • Grant A.
  • Mamyshev P.
  • Mollenauer L.

We describe a simple scheme to allow for the achievement of flat gain over very broad gain bands with backward-pumped Raman amplification. The proposed method also allows for dynamic gain control through simple electronic means.

Effect of Cracks in TiN Anti-Reflection Coating Layers on Early via Electromigration Failure

  • Brown W.
  • Huang J.
  • Oates A.
  • Zhao J.

Due to the increased circuit current densities and temperatuers, interconnect reliability continues to be one of the major reliability concerns with the progress of device scaling. Electromigration has received extensive study because electromigration failure becomes increasingly serious in multi-level structure, which have been employed to achieve higher interconnect cirucit densities ...

On the Orthographic Dimension of Definable Sets

  • Cosmadakis S.
  • Kuper G.
  • Libkin L.

A formula phi (chi sub 1,...,chi sub n) conforms to a partition P of {chi sub 1,...,chi sub n} if it is equivalent to a Boolean combination of formulae that do not have free variables from more than one block of P. We show that if phi conforms to two ...

Low-Power, Small-Footprint Gigabit-Ethernet-Compatible Optical Receiver Circuit in 0.25 micron CMOS

  • Krishnamoorthy A.
  • Lentine A.
  • Rozier R.
  • Woodward T.

We present experimental results for a photo-receiver circuit capable of operating with gigabit Ethernet signals and generating full CMOS logic levels. A dc-coupled single-ended pre-amplifier is coupled with an averaging capacitor to a differential post-amplifier that uses inverse scaling to increase bandwidth. The circuits are realized in 0.25 micron CMOS, ...

Fractional Quantum Hall Effect in Organic Molecular Semiconductors

  • Batlogg B.
  • Kloc C.
  • Schon H.

High quality crystals of the organic molecular semiconductors tetracene and pentacene are used to prepare metal-oxide-semiconductor (MOS) structures exhibiting hole as well as electron mobilities exceeding 10 sup 4 square centimeter per volt per second. The carrier concentration in the channel region of these ambipolar field-effect devices is controlled by ...

Evolution of the Beam Diameter in a Multimode Fiber Link Through Offset Connectors

  • Giaretta G.
  • Golowich S.
  • Nuss M.
  • Wegmuller M.

We find that using an overfilled launch, transmission of an 8 Gb/s NRZ signal can suffer a significant power penalty due to modal noise or fiber bandwidth fluctuations if an offset connector is located before the 300 m long multimode fiber link. This is an important problem as multimode fiber ...

Bismuth Titanium Indium Antimony Oxide: A Low Temperature Coefficient, High K Dielectric Material

  • Cava R.
  • Krajewski J.
  • Qin Y.
  • Zandbergen H.

The 1 MHz dielectric properties for mixed phase polycrystalline ceramics of composition Bi sub 5 Ti sub 3 In sub x Sb x sub (1-x) O sub (15) are reported. In the vicinty of ambient temperature, the dielectric constants for the Sb and In end-members are approximately 430 and 160, ...

On Holographic Transform Compression of Images

  • Bruckstein A.
  • Holt R.
  • Netravali A.

Lossy transform compression of images is very successful and widespread. The JPEG standard uses the discrete cosine transform on blocks of the image and a bit allocation process that takes advantage of the uneven energy distribution in the transform domain. For most images 10:1 compression ratios can be achieved with ...

What Angle-Resolved Photoemission Experiments Tell About the Microscopic Theory for High-Temperature Superconductors

  • Abrahams E.
  • Varma C.

The discovery of the copper oxide superconducting materials in 1987 and the intense investigations which followed have raised some fundamental questions in condensed mater physics. These superconductors are characterized by two unexpected features. One is, of course, their unprecedented high transition temperatures (T sub c). In addition it is clear ...

Representation Theory for High-Rate Multiple-Antenna Code Design

  • Hassibi B.
  • Hochwald B.
  • Shokrollahi A.
  • Sweldens W.

Multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially on our ability to design high-rate space-time constellations with low encoding and decoding complexity. It has been shown that full transmitter ...

Ultra-High Capacity 40-Gb/s WDM Systems

  • Nielsen T.

The demonstrated capacity of 40-Gb/s WDM systems is now exceeding 3-Tb/s. We will discuss some of the enabling technologies for these high capacities and some of the technologies that may push the aggregate capacity of WDM systems towards 10-Tb/s.

Carbon Doping of InAlAs in LP-MOVPE Using CBr sub 4

  • Geva M.
  • Holavanahalli J.
  • Ougazzaden A.
  • Smith L.

P-type InAlAs material is used in several microelectronic and optoelectronic devices such as heterojunction bipolar transistors (1) and laser (2). Using carbon as the p-dopant provides two advantages over Zn, the commonly used p-dopant: high incorporation efficiency in InAlAs, and very limited out-diffusion. Only a few studies have been reported ...

Gate Oxide Reliability Projection to the Sub-2nm Regime

  • Alam M.
  • Baumann F.
  • Brown M.
  • Bude J.
  • Diodato P.
  • Ghetti A.
  • Hamad A.
  • Hwang D.
  • Ma Y.
  • Mason P.
  • Monroe D.
  • Silverman P.
  • Sorsch T.
  • Timp G.
  • Weir B.

As the silicon industry moves forward, smaller devices with lower operating voltage and thinner gate oxides are being manufactured. To investigate the limit below the which it will be impossible for the gate oxide layer to have sufficient intrinsic reliability, we have studied ultra-thin oxides below previous projected limit of ...

Hydrogen Bonding in Urea

  • Hamann D.
  • Isaacs E.
  • Platzman P.
  • Shukla A.

The hydrogen bond consisting of a Hydrogen atom positioned asymmetrically between a Nitrogen and Oxygen atom (O...H-N) plays a central role in the structure and functionality of proteins and amino acids. In particular, the Urea crystal is perhaps the simplest system in which such a hydrogen bond exists. We have ...

Passive Reduced-Order Modeling via Krylov-Subspace Methods

  • Freund R.

In recent years, Krylov-subspace methods have become popular tools for computing reduced-order models of large-scale time-invariant linear dynamical systems. These techniques produce in a Pade sense optimal reduced-order models. However, when applied to passive systems, the Pade models do not preserve passivity in general. In this paper, we describe a ...