The physics of dipolar bosonic quantum gases

This article reviews the recent theoretical and experimental advances in the study of ultracold gases made of bosonic particles interacting via the long-range, anisotropic dipole-dipole interaction, in addition to the short-range and isotropic contact interaction usually at work in ultracold gases. The specific properties emerging from the dipolar interaction are emphasized, from the mean-field regime valid for dilute Bose-Einstein condensates, to the strongly correlated regimes reached for dipolar bosons in optical lattices.Comment: Review article, 71 pages, 35 figures, 350 references. Submitted to Reports on Progress in Physic

PMD induced transmission penalties in polarization multiplexed transmission

In this paper, we investigate for the first time chromatic dispersion and nonlinearity tolerances in the presence of polarization-mode dispersion (PMD) for polarization-multiplexed (POLMUX) 2 × 10-Gb/s nonreturn-to-zero (NRZ) transmission. In polarization-multiplexing, the interaction between fiber nonlinearity and PMD can lower the nonlinear tolerance beyond the tolerances evident when considering both transmission penalties separately; the combined penalties are significantly worse than in the case for non-POLMUX transmission. In this paper, we show, through simulations comparing POLMUX with non-POMUX transmission in the presence of nonlinearity, a reduction of about a factor of three in PMD tolerance. In addition, we show that the dispersion tolerance of POLMUX transmission is severely limited in the presence of PMD. For example, a 40-ps differential group delay (DGD) with worst case coupling of the polarization channels into the fiber lowers the dispersion tolerance, resulting in a 1-dB eye-opening penalty (EOP), from 1200 to 450 ps/nm. We conclude that the interaction between PMD, chromatic dispersion, and nonlinearity leads to the worst signal impairments in POLMUX transmission and increases the effort of using polarization-multiplexing as a modulation format. © 2005 IEEE

PMD and nonlinearity-induced penalties on polarization-multiplexed transmission

We investigate penalties induced by polarization-mode dispersion (PMD) and the interaction between PMD and fiber nonlinearity on polarization-multiplexed transmission through both simulations and experiment. We find that controlling the phase difference between polarization channels can enhance the PMD tolerance in polarization-multiplexed transmission

Polarization interleaving to reduce inter-channel nonlinear penalties in polarization multiplexed transmission

We investigate through simulations and experiments inter-channel nonlinear penalties in 2×10Gbit/s NRZ polarization-multiplexed transmission. We show that the inter-channel nonlinear penalties can be partially mitigated by polarization interleaved transmission of the polarization-multiplexed channels

PMD-Induced Transmission Penalties in

In this paper, we investigate for the first time chromatic dispersion and nonlinearity tolerances in the presence of polarization-mode dispersion (PMD) for polarization-multiplexed (POLMUX) 2 10-Gb/s nonreturn-to-zero (NRZ) transmission. In polarization-multiplexing, the interaction between fiber nonlinearity and PMD can lower the nonlinear tolerance beyond the tolerances evident when considering both transmission penalties separately; the combined penalties are significantly worse than in the case for non-POLMUX transmission. In this paper, we show, through simulations comparing POLMUX with non-POMUX transmission in the presence of nonlinearity, a reduction of about a factor of three in PMD tolerance. In addition, we show that the dispersion tolerance of POLMUX transmission is severely limited in the presence of PMD. For example, a 40-ps differential group delay (DGD) with worst case coupling of the polarization channels into the fiber lowers the dispersion tolerance, resulting in a 1-dB eye-opening penalty (EOP), from 1200 to 450 ps/nm. We conclude that the interaction between PMD, chromatic dispersion, and nonlinearity leads to the worst signal impairments in POLMUX transmission and increases the effort of using polarization-multiplexing as a modulation format

IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 17, NO. 6, JUNE 2005 1337 Reduction of Nonlinear Penalties Through

We simulated the nonlinear transmission penalties induced through cross-phase modulation related depolarization in 2 10 Gb/s polarization-multiplexed (POLMUX) transmission. We find that launching adjacent wavelength-division-multiplexed channels with a 180 relative state of polarization shift results in a significant decrease in nonlinear transmission penalties and allows for longer distance POLMUX transmission

Nonlinear tolerance of differential phase shift keying modulated signals reduced by XPM

We show that in order to maintain the high nonlinear tolerance of the DQPSK modulation format, XPM from neighboring OOK-modulated channels must be avoided. The negative impact on 10Gb/s DQPSK channels is higher than at 20Gb/s

Nonexponential decay of Bose-Einstein condensates: a numerical study based on the complex scaling method

We study the decay dynamics of an interacting Bose�Einstein condensate in the presence of a metastable trapping potential from which the condensate can escape via tunneling through finite barriers. The time-dependent decay process is reproduced by means of the instantaneous decay rates of the condensate at a given population of the quasi-bound state, which are calculated with the method of complex scaling. Both for the case of a double-barrier potential as well as for the case of a tilted periodic potential, we find pronounced deviations from a monoexponential decay behavior, which would generally be expected in the absence of the atom�atom interaction