Dispersion remains, today, a highly topical subject. Our group has been interested in characterizing this phenomenon by pulsed-field-gradient NMR technique. Direct measurement of the dispersion coefficient can be done with a Pulsed Gradient Spin Echo (PGSE) sequence by assuming that the asymptotic regime is reached. In unsteady state, the propagator formalism is used. To better understand these...

We experimentally demonstrate a digital signal processing (DSP)-based optical performance monitoring (OPM) algorithm for in-service monitoring of chromatic dispersion (CD) in coherent transport networks. Dispersion accumulated in 40 Gbit/s QPSK signal after 80 km of fiber transmission is successfully monitored and automatically compensated without prior knowledge of fiber dispersion coefficient...

We consider the weakly dissipative and weakly dispersive Burgers-Hopf-Korteweg-de-Vries equation with the diffusion coefficient ε and the dispersion rate δ in the range δ/ε → 0. We study the travelling wave connecting u(−∞) = 1 to u(+∞) = 0 and show that it converges strongly to the entropic shock profile as ε, δ → 0. Key-words Travelling waves, moderate dispersion, Korteweg de Vries equation, ...

The effluent treatment plant sludge is one of the major sources of contamination with toxic metals. Since the sludge contains heavy metals, it must be pretreated to reduce the contamination. The heavy metals from the sludge can be reduced/ separated by washing it with a suitable leaching solution. In the present study, the efficiencies of three leaching solutions to remove the contaminants from...

We propose a new type highly birefringent spiral photonic crystal fiber (PCF) for residual dispersion compensation in a wide range of wavelengths. The 2-D finite element method (FEM) with perfectly matched boundary layer (PML) is used for numerical simulation. The arrangement and diameter of circular air holes in the designed PCF has been tuned to offer almost flat dispersion profile with avera...

We demonstrate the generation of a supercontinuum in a 2 cm long silicon wire by pumping the wire with mid-infrared picosecond pulses in the anomalous dispersion regime. The supercontinuum extends from 1535 nm up to 2525 nm for a coupled peak power of 12.7 W. It is shown that the supercontinuum originates primarily from the amplification of background noise. A detailed analysis of the spectral ...

A nonlinear coefficient of 3.6-4.1  W-1  km-1 and group velocity dispersion of -20  ps2/km of a commercial core-pumped thulium-doped fiber have been evaluated using degenerate four-wave mixing at 2 μm. The anomalous dispersion behavior of the fiber has been confirmed by linear measurements with an all-fiber Mach-Zehnder interferometer (MZI). Additionally, no pum...

The longitudinal response function for an isotropic, nonrelativistic, thermal plasma with the quantum recoil included exactly is used to generalize the dispersion relation for ion acoustic waves and the absorption coefficient for Landau damping to include the quantum recoil. The results are compared to recent treatment of the dispersion relation derived using a fluid theory with the quantum eff...

We present a theoretical investigation of the stability properties of semiconductor lasers with strong feedback from dispersive extended cavities. Surprisingly, unstable behavior had been observed experimentally for chirped fiber grating lasers, where the stability of the laser was found to depend upon the orientation of the fiber grating. We reproduce this finding through a linear stability an...

We report on the theoretical and experimental study of the generation of propagating waveguide modes on the water surface. These propagating modes are modulated in the transverse direction in a manner that satisfies boundary conditions on the walls of the water tank. It is shown that the propagating modes possess both anomalous and normal dispersion regimes, in contrast to the extensively studi...