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A dual parallel Mach?Zehnder modulator (DPMZM) used for electro-optic conversion of multi-band orthogonal frequency-division multiplexing (OFDM) ultra-wideband (UWB) radio signals in intensity modulated direct detection optical communication systems is optimized theoretically and through numerical simulation. The optimum DPMZM parameters that allow simultaneous mitigation of the second and third order distortion components created by the joint electro-optic converter and photodiode nonlinearities are identified. The corresponding minimum optical signal-to-noise ratio (OSNR) required to achieve a bit error ratio of 10-9 is also evaluated. An analytical expression showing the relation between the optimum DPMZM parameters under extended voltage levels of the OFDM-UWB signals applied to the DPMZM is proposed and validated. It is shown that the DPMZM performance presents high robustness to deviations from the optimum DPMZM parameters identified. Additionally, it is shown that similar minimum required OSNR levels are obtained with the optimized DPMZM and when the electro-optic conversion is realized by a single MZM. [ABSTRACT FROM PUBLISHER]

The impact of the switching window shape on the performance of a chain of reamplification, reshaping, and retiming all-optical regenerators based on a non-linear gate is investigated numerically. A method to estimate the chain performance that considers the amplitude fluctuations due to timing jitter and noise redistribution along the chain is proposed. The results show that the rectangular switching window is not appropriate for reamplification, reshaping, and retiming regenerators, and the optimum shape of the switching window depends on the number of regenerators of the chain, optical noise power, and timing jitter levels. [ABSTRACT FROM AUTHOR]

A transparent optical network (TON) composed by optical add-drop multiplexers based on arrayed waveguide grating (AWG) with fabrication errors is optimized for 10 Gbit/s per channel and channel spacing of 25 GHz. The optimization takes into account the effect of inter-symbol interference, amplified spontaneous emission noise accumulation, and coherent and incoherent homodyne crosstalk. Numerical results reveal that AWG fabrication errors can have a high influence on the TON performance; however, in all investigated situations, they do not affect the AWG parameters values corresponding to the optimum AWG frequency response. This surprising behavior is due to the fabrication errors affect mainly the AWG response outside the passband for the required AWG crosstalk level. It is shown that the optimum AWG frequency response is a flat-top response with a mean amplitude response outside the passband lower than -30 dB and the switch isolation should exceed 30 dB. [ABSTRACT FROM AUTHOR]

This article introduces the main achievements resulting from the DWDM/ODC project. The five areas of research activity within the DWDM/ODC project cover some of the main issues of design and development of dense wavelength division multiplexing systems for transparent optical networks. These issues are: performance assessment with arbitrary optical filtering; performance of signaling formats; dispersion compensation strategies for directly and externally modulated systems in presence of nonlinear transmission-induced degradation; and the impact of noise and crosstalk in the extent of transparent optical networks. All five areas of research activity have contributed significantly to a better understanding of the limitations present in dense wavelength division multiplexing systems. [ABSTRACT FROM AUTHOR]

The correlation and power distribution of intercore crosstalk (ICXT) field components of weakly coupled multicore fibers (WC-MCFs) are important properties that determine the statistics of the ICXT and ultimately impact the performance of WC-MCF optical communication systems. Using intensive numerical simulation of the coupled mode equations describing ICXT of a single-mode WC-MCF with intracore birefringence and linear propagation, we assess the mean, correlation, and power distribution of the four ICXT field components of unmodulated polarization-coupled homogeneous and quasi-homogeneous WC-MCFs with a single interfering core in a wide range of birefringence conditions and power distribution among the field components at the interfering core input. It is shown that, for homogeneous and quasi-homogeneous WC-MCFs, zero mean uncorrelated ICXT field components with similar power levels are observed for birefringence correlation length and birefringence beat length in the ranges of 0.5 m , 10 m and 0.1 m , 10 m , respectively, regardless of the distribution of power between the four field components at the interfering core input. [ABSTRACT FROM AUTHOR]

In this work, we propose to use four-level pulse amplitude modulation (PAM4) and multi-core fibers (MCFs) to support very high capacity datacenter interconnect (DCI) links. The limitations imposed by inter-core crosstalk (ICXT) on the performance of 112 Gb/s up to 80 km-long optically amplified PAM4 inter-DCI links with intensity-modulation and direct-detection and full chromatic dispersion compensation in the optical domain are analyzed through numerical simulation for high and low skew-symbol rate product (SSRP). With only one interfering core, we show that those PAM4 inter-DCI links achieve an outage probability (OP) of 10 − 4 with a maximum ICXT level of −13.9 dB for high SSRP and require an ICXT level reduction of about 8.1 dB to achieve the same OP for low SSRP. Due to using full dispersion compensation, for an OP of 10 − 4 , the maximum acceptable ICXT level shows only a 1.4 dB variation with the MCF length increase from 10 km to 80 km. When considering the ICXT induced by several interfering cores, the maximum ICXT level per interfering core for an OP of 10 − 4 decreases around 3 dB when doubling the number of interfering cores. This conclusion holds for high and low SSRP regimes. For two interfering cores, we show that a single interfering core with low SSRP is enough to induce a severe reduction of the maximum acceptable ICXT level. [ABSTRACT FROM AUTHOR]