Moment Equations for Optical Pulses in Dispersive and Dissipative Systems

  • Kozlov M.
  • Mckinstrie C.

The moment method is used to derive evolution equations for the energy, width and chirp of an optical pulse in a dispersive and dissipative (filtered) system. This method is conceptually simpler than the variational and soliton- perturbation methods, and allows the dispersion and dissipation coefficients to have arbitrary relative magnitude.

Spin Dynamics of Sr14Cu24O41 Two-Leg Ladder Studied by Raman Spectroscopy

  • Blumberg G.
  • Dennis B.
  • Eisaki H.
  • Gozar A.
  • Motoyama N.
  • Shastry B.
  • Uchida S.

The two-magnon (2M) excitation at 3000 cm21 in Sr14Cu24O41 two-leg ladder is studied by Raman scattering. A slight anisotropy of the superexchange coupling JXXJk X 0.8 with Jk X 110 6 20 meV is proposed from the analysis of the magnetic scattering. The resonant coupling across the charge transfer gap ...

Nonmonotonic dx22y2 Superconducting Order Parameter in Nd22xCexCuO4

  • Blumberg G.
  • Dennis B.
  • Fournier P.
  • Gozar A.
  • Greene R.
  • Kendziora C.
  • Koitzsch A.

Low energy polarized electronic Raman scattering of the electron- doped superconductor Nd22xCexCuO4 (x 0.15, Tc 22 K) has revealed a nonmonotonic dx22y2 superconducting order parameter. It has a maximum gap of 4.4kBTc at Fermi surface intersections with an antiferromagnetic Brillouin zone (the "hot spots") and a smaller gap of 3.3kBTc ...

Antiferromagnetism in CaCu3Ti4O12 studied by magnetic Raman spectroscopy

  • Blumberg G.
  • Dennis B.
  • Gozar A.
  • Koitzsch A.
  • Ramirez A.
  • Trebst S.
  • Wakimoto S.

For CaCu3Ti4O12—an insulator that exhibits a giant dielectric response above 100 K—Cu21 antiferromagnetic spin ordering has been investigated by magnetic Raman scattering and magnetization measurements. Below the Ne´el temperature, TN525 K, magnetic excitations have been identified. Above TN Raman spectra reveal short-range antiferromagnetic fluctuations that increase with cooling like T21. ...

Long-Term Wavelength Switching Measurements with Random Schedules on Fast Tunable Lasers

  • Bhardwaj A.
  • Gripp J.
  • Simsarian J.
  • Zirngibl M.

We demonstrate 26 hours of error-free wavelength switching in less than 50 ns between 32 ITU channels with 100 GHz spacing using a GCSR laser. This corresponds to a packet-loss rate of less than 2*10-11. We also examine the effect of different switching schedules, an important issue for commercial switch ...

Building Edge-Failure Resilient Networks

  • Chekuri C.
  • Gupta A.
  • Kumar A.
  • Naor J.

We consider the design of resilient networks that are fault tolerant against single link failures. Resilience against single link failures can be built into the network by providing backup paths, which are used when an edge failure occurs on a primary path. We consider several network design problems in this ...

Spectral Monitoring of OSNR in High-Speed Networks

  • Agarwal A.
  • Buhl L.
  • Chandrasekhar S.
  • Kilper D.
  • Maywar D.

The conditions under which the optical spectrum can be used for performance monitoring of the OSNR are determined for 10 and 40 Gb/s networks with high spectral efficiency and optical add-drop multiplexers


  • Chandrasekhar S.
  • Winzer P.

Simulations and measurements at 40Gbit/s show that RZ-DPSK is more robust to narrow-band optical filtering than on/off keying (OOK), in particular if balanced DPSK detection is employed.

Forward Error Correction Performance in Presence of Rayleigh-Dominated Transmission Noise

  • Chandrasekhar S.
  • Radic S.
  • Srivastava A.
  • Velingker A.
  • Vukovic N.

Performance of Forward Error Correction (FEC) scheme is investigated in presence of Rayleigh induced optical noise. Signal coherence and mutual polarization states of signal and Rayleigh backscatter are found to strongly influence the performance of the transmission architecture.

Interfacial Chemistries for Nanoscale Transfer Printing

  • Baldwin K.
  • Loo Y.
  • Rogers J.
  • Willett R.

We have devised a contact printing technique for transferring functional materials from the raised regions of a stamp onto a substrate. The process relies on using self-assembled monolayers as “glues” and “release layers” for pattern transfer. This technique is purely additive and it readily prints nanometer length scale features. Furthermore, ...

Molecular beam epitaxy of GaN/AlxGa1-xN multiple quantum wells on R-plane (10 12) sapphire substrates

  • Ng H.

GaN/Al0.15Ga0.85N multiple quantum wells (MQWs) have been grown by plasma-assisted molecular beam epitaxy on R-plane (10 12) sapphire substrates. The orientation relationship was found to be (11 20) (Al)GaN || (10 12) Al2O3, resulting in non-polar GaN/AlGaN heterostructures. Room temperature photoluminescence studies were performed to compare the optical properties of ...


  • Xie C.

The performance of distributed PMD compensation in the transmission line is evaluated, and it is shown that the tolerable PMD increases almost linearly with the number of PMD compensators distributed in the transmission line.

Cross-Phase-Modulation-Induced Nonlinear Phase Noise in WDM Direct-Detection DPSK Systems

  • Kim H.

In direct-detection differential-phase-shift-keying (DPSK) systems, the signal-spontaneous beat noise introduces phase noise due to Kerr nonlinearity. In wavelength-division-multiplexed (WDM) systems, this nonlinear phase noise comes not only from the channel itself through self-phase modulation (SPM) but also from the other channels through cross-phase modulation (XPM). In this paper, we theoretically ...

Generation of Low-frequency Components Due to Phase-amplitude Modulation of Subcycle Far-infrared Pulses in Near-field Diffraction

  • Mitrofanov O.
  • Pfeiffer L.
  • West K.

We observe carrier phase dependent generation of low-frequency spectral components in the near-field zone of a subwavelength aperture illuminated by subcycle far-infrared (terahertz) pulses. Diffraction induced II/2-phase shift of the pulse carrier results in the spectral intensity variation of the low-frequency components. The effect demonstrates that spectral content of subcycle ...

Gaussian Fields and Random Packing

  • Baryshnikov Y.
  • Yukich J.

Consider sequential packing of unit volume balls in a large cube, in any dimension and with Poisson input. We show after suitable rescaling that the spatial distribution of packed balls tends to that of a Gaussian field in the thermodynamic limit. The results cover related applied models, including ballistic deposition ...

Route Oscillations in I-BGP with Route Reflection

  • Basu A.
  • Ong C.
  • Rasala A.
  • Shepherd F.
  • Wilfong G.

We study the route oscillation problem~cite{MGW00,Cis00} in the Internal Border Gateway Protocol (I-BGP)~cite{RL95} when route reflection is used. We propose a formal model of I-BGP and use it to show that even deciding whether an I-BGP configuration with route reflection can converge is an NP-Complete problem. Finally, we propose a ...

TCP/IP Performance over 3G Wireless Links with Rate and Delay Variation

  • Chan M.
  • Ramjee R.

Wireless link losses result in poor TCP throughput since losses are perceived as congestion by TCP, resulting in source throttling. In order to mitigate this effect, 3G wireless link designers have augmented their system with extensive local retransmission mechanisms. In addition, in order to increase throughput, intelligent channel state based ...


  • Girault M.
  • Kauer M.
  • Zirngibl M.

We present a 16-channel 100 GHz-spacing digitally tunable packet switching transmitter based on an external-cavity laser. The transmitter can switch within 0.8 ns between its channels at 0 dBm output power and <0.7 dB penalty.

Performance Analysis of Call Assignment and Carrier Packing Schemes for TDMA Systems

  • Budka K.
  • Kaufman J.
  • Kodialam M.
  • Sampath A.

In IS-136 and GSM TDMA systems that employ dynamic channel allocation, it is important to minimize the number of active carriers for a given load. This memorandum studies the carrier packing properties of both call assignment and carrier repacking schemes, where the average number of active carriers and the average ...

Influence of Scattering on Transmission Through Long-Period Fiber Gratings and Tunable, Microstructure Fibers

  • Eggleton B.
  • Kerbage C.
  • Mach P.
  • Rogers J.
  • Windeler R.

Controlled optical scattering within or around an optical fiber provides a potentially useful means for adjusting its transmission characteristics. This approach can complement conventional methods based on establishing well defined variations in the index of refraction of the core or the cladding of the fiber. This paper describes the use ...