Showing papers by "Er'el Granot published in 2012"

Generic pattern formation of sharp-boundaries pulses propagation in dispersive media

Abstract: In optical communication, pulses have approximately a rectangular shape with smooth boundaries. In order to understand the dynamics of these pulses: (A) the generic dynamics of singular quantum mechanics’ wave functions was applied to sharp-boundaries pulses propagation in short dispersive medium and (B) an analytical expression for the propagation of a smooth rectangular pulse in dispersive medium was derived. This analytical expression consists of a couple of complex error functions and can be applied in good approximation to most rectangular pulses propagations in dispersive medium. (C) An analytical approximation was derived for the propagation of any pulse with sharp boundaries. This approximation, despite being analytical, can be applied to any sharp-boundaries pulse with any given shape. These exact expressions and approximations can be used in other systems where the Schrodinger dynamics hold, such as the paraxial approximation.

Fundamental dispersion limit for spectrally bounded On-Off-Keying communication channels

Abstract: The fundamental dispersion limit for optical communication based the On-Off-Keying format is calculated. It is shown both analytically and with numerical simulations that an OOK optical sequence, which passes through spectrally narrow noncompensated dispersive channel cannot exceed the limit 1/{\pi} > {\beta_2} L B^2, where {\beta_2}, L and B are the dispersion coefficient, the fiber's length and the bit-rate respectively. To the best of our knowledge, this is the first time that such a fundamental limit was formulated. In the literature, only approximation evaluations were developed yielding much smaller limiting values.

Fundamental dispersion limit for spectrally bounded On-Off-Keying communication channels and its implications to Quantum Mechanics and the Paraxial Approximation

Abstract: The fundamental dispersion limit for an optical communication based the On-Off-Keying format is calculated. It is shown both analytically and with numerical simulations that an OOK optical sequence, which passes through a spectrally narrow non-compensated dispersive channel cannot exceed the limit β 2 B2L < π - 1 , where β 2 , L and B are the dispersion coefficient, the fiber's length and the bit rate, respectively. To the best of our knowledge, this is the first time that such a fundamental limit was formulated. In the literature, only approximation evaluations were developed yielding much smaller limiting values. Since this fundamental limit is a manifestation of the Schrodinger equation, a correspondingly similar limit emerges in Quantum Mechanics and in the optical Paraxial Approximation.

Comparison between spectral optical coherence tomography and the FFT-based impulse-response reconstruction method in the transmission configuration

Abstract: We present a comparison between the well-known spectral optical coherence tomography (SOCT) technology and the fast-Fourier-transform-based (FFT-based) impulse-response reconstruction method (FIRRM), which we developed—both in the transmission configuration. It is shown that, since the transmission configuration requires relatively long interferometers, the SOCT measurements are less stable than those of the FIRRM, as seen in the impulse-response reconstruction of the two methods. The FIRRM results show much better agreement with theoretical predictions.

Partial Differential Phase Shift Keying - Theory and Motivation

Abstract: Recently, many evidences demonstrate that partial Differential Phase Shift Keying (i.e., when the delay inside the Delay Interferometer is shorter than the symbol period) can partially compensate the signal deformation caused by spectrally narrowing the optical channel (by interleavers, add-drop elements, WDM filters, etc.). In this paper the source of this effect is investigated with numerical simulations and, to the best of our knowledge for the first time, analytically. We found that our analytical analysis matched the simulation results with high accuracy. Furthermore, a phenomenological relation, which relates the optimum Free Spectral Range to the channel bandwidth, was derived.