Showing papers by "Antonio Mecozzi published in 2000"
TL;DR: In this paper, the authors analyzed intrachannel nonlinear effects in high-bit-rate transmission systems based on short optical pulses that are dispersion compensated and showed that the magnitude of nonlinear impairments reduces monotonically with the reduction of pulse width and with the increase of the dispersion coefficient.
Abstract: We analyze intrachannel nonlinear effects in high-bit-rate transmission systems based on short optical pulses that are dispersion compensated. We perform an analytical study of a generic example with two pulses, in which case the nonlinearity shifts the pulses in time and results in the generation of leading and trailing pulse echoes. We show that in all the relevant range of parameters, the magnitude of the nonlinear impairments reduces monotonically with the reduction of pulse width and with the increase of the dispersion coefficient.
259 citations
TL;DR: In this paper, the authors provide accurate estimates of timing and amplitude jitter caused by nonlinear pulse interaction in systems based on highly dispersed optical pulses, both for coherent and non-coherent pulse streams.
Abstract: We provide accurate analytical estimates of timing- and amplitude-jitter caused by nonlinear pulse interaction in systems based on highly dispersed optical pulses, both for coherent and noncoherent pulse streams. We show that the system penalties reduce monotonically with pulsewidth and with increasing fiber dispersion. We demonstrate that proper dispersion pre-compensation can result in a significant reduction of the nonlinear inpairments and provide analytical tools for obtaining the optimal pre-compensation parameters.
100 citations
TL;DR: In this paper, a computer simulator of semiconductor optical amplifiers is presented, where the nonlinear input-output response of the device is characterized in terms of a complex gain, representing the accumulated gain and wavevector change of the propagating field across the active waveguide.
Abstract: We present a computer simulator of semiconductor optical amplifiers. The nonlinear input-output response of the device is characterized in terms of a complex gain, representing the accumulated gain and wavevector change of the propagating field across the active waveguide. We account for the gain saturation induced by stimulated recombination and by the perturbation of the carrier quasi-equilibrium distribution within the bands. A rigorous elimination of the spatial coordinate allows us to reduce the description of the amplifier dynamics to the solution of a set of ordinary differential equation for the complex gain. If the waveguide internal loss is negligible, the spatial inhomogeneity of the complex gain is implicitly yet exactly taken into account by the reduced model. The accuracy of the reduced model is the same for models based on the direct solution of the set of partial differential equations describing the interaction between the optical field and the active semiconductor waveguide, but the model is computationally much simpler. To preserve the input-output characteristics of the model, we include the amplified spontaneous emission noise in the device description by an equivalent signal applied to the device input and amplified by the saturated gain. At the expense of a minor increase of the program complexity, the waveguide internal loss may also be included. We report on the comparison between the output of the simulator and the results of four-wave mixing experiments in various pump-signal configurations. Good agreement is obtained.
89 citations
TL;DR: In this article, the authors derive the signal bandwidth below which the first-order approximation of the principal states of polarization is valid, and show that this bandwidth depends only on the mean value of the differential group delay.
Abstract: Using the retarded plate model, we derive the correlations and the mean-square values of all orders of polarization mode dispersion (PMD) as well as the autocorrelation function of the PMD vector. Our results provide the signal bandwidth below which the first-order approximation of the principal states of polarization is valid. We show that this bandwidth depends only on the mean value of the differential group delay. Our theoretical results are supported by simulations and experiments.
76 citations
TL;DR: In this paper, a polarization mode dispersion compensator for the rotation of the principal states with frequency is proposed. But the compensator requires only two control elements more than existing first-order compensators, i.e., the position of one polarization controller and a single delay.
Abstract: We present a polarization mode dispersion compensator for the rotation of the principal states with frequency. This compensator requires only two control elements more than existing first-order compensators. These are the position of one polarization controller and the setting of a single delay. With the proposed scheme, compensation for first order can be decoupled from the compensation for higher orders and controlled independently. The effect of the compensator on signal transmission is evaluated with extensive numerical simulations.
74 citations
TL;DR: It is shown that the correlation bandwidth of the differential group delay is comparable with that of the orientation of the PMD vector, and all the most general statistical properties of polarization mode dispersion in long fibers are uniquely determined by the mean DGD.
Abstract: We study the frequency autocorrelation of the differential group delay (DGD) in fibers with polarization mode dispersion (PMD). We show that the correlation bandwidth of the DGD is comparable with that of the orientation of the PMD vector. Furthermore, we show that all the most general statistical properties of polarization mode dispersion in long fibers are uniquely determined by the mean DGD. An estimate of the accuracy of measurements in which the mean DGD is extracted by frequency averaging in a single fiber is obtained as a function of the measured bandwidth.
61 citations
TL;DR: In this paper, the quantum theory of noise in a chain of gain-loss elements is reviewed and a new derivation of the characteristic function of the photon-number distribution at the output of a long amplifier chain is given.
Abstract: The quantum theory of noise in a chain of gain–loss elements is reviewed. A new derivation is given of the characteristic function of the photon-number distribution at the output of a long amplifier chain. The results of the quantum theory are compared with those of the semiclassical theory, and it is shown that in most practical cases the semiclassical theory gives an excellent approximation of the full quantum result. It is shown that transparency sets a fundamental limit on the maximum distance over which a signal can be transmitted and hence on the maximum spacing between regenerative stations. An analytic estimate of this limit is given.
11 citations
07 Mar 2000
TL;DR: In this article, a PMD compensator for the rotation of the principal states with frequency is presented, which requires only two control parameters more than existing first-order compensators.
Abstract: We present a PMD compensator for the rotation of the principal states with frequency. It requires only two control parameters more than existing first order compensators. The compensation for first order is decoupled from the compensation for high orders and is controlled independently.
9 citations
14 Jul 2000
TL;DR: In this article, a systematic expansion of the polarization equation and staying within a third-order [(chi) (3 )] regime are derived explicit corrections to the response function due to non-adiabatic effects.
Abstract: The adiabatic elimination of the polarization dynamics often invoked in treatments of pulse propagational and pulse interactions in semiconductor optical waveguides is critically investigated. By employing a systematic expansion of the polarization equation and staying within a third-order [(chi) (3 )] regime we are able to derive explicit corrections to the response function due to non-adiabatic effects. Several such effects are identified and analyzed. This provides a unified view of different results reported previously in the literature, but also identifies a new effect which apparently hasn't been analyzed so far. The effect relates to virtual excitation of the total carrier density, as opposed to the well-known adiabatic following effect of individual two-level systems, and we derive simple analytical expressions that relate this effect to the gain and index dispersion. We find it to give a sizable contribution to the well-known instantaneous effects of two-photon absorption and Kerr nonlinearity.
7 citations
TL;DR: In this article, interval-polarization-independent wavelength conversion at 2.5 Gb/s using four-wave mixing in a single semiconductor optical amplifier was obtained with a dual-pump configuration in a bidirectional geometry.
Abstract: We report interval-polarization-independent wavelength conversion at 2.5 Gb/s using four-wave mixing in a single semiconductor optical amplifier. These results have been obtained with a dual-pump configuration in a bidirectional geometry. Bit-error-rate (BER) curves are reported for a conversion shifts of -1 and +1 THz. The signal polarization was automatically scrambled during the BER measurement. The penalty with respect to the back-to-back line is 2.4 and 1.6 dB, respectively.
6 citations
07 May 2000
TL;DR: The realisation of an SOA simulator based on a novel approach talcing into account longitudinal spatial hole burning without solving partial differential equations or using split-step algorithms is described.
Abstract: Summary form only given.In optical networks based on wavelength-division multiplexing (WDM), semiconductor optical amplifiers (SOA) are ideal candidates for all-optical signal processing. The simulation of an SOA inserted in an optical system is a relevant task aimed to the realization of computer packages for optical system simulation. We describe the realisation of an SOA simulator based on a novel approach talcing into account longitudinal spatial hole burning without solving partial differential equations or using split-step algorithms. We will give results ofsimulations and compare them with experimental results.
07 Mar 2000
TL;DR: Polarization-independent four-wave mixing is obtained in semiconductor optical amplifiers by splitting the incoming fields with a polarization beam splitter and injecting the resulting counter-propagating beam in the amplifier.
Abstract: Polarization-independent four-wave mixing is obtained in semiconductor optical amplifiers by splitting the incoming fields with a polarization beam splitter and injecting the resulting counter-propagating beam in the amplifier.