Nelson J. Muga

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We review the research progress concerning some fundamental issues related to polarization-mode dispersion (PMD) in high-speed fiber-optic transmission systems. We pay particular attention to issues such as the PMD-induced pulse broadening , PMD measurement and emulation, as well as PMD compensation. An electrical equalization technique based on a(More)
We report our recent advances in the implementation of very high-speed optical channels (targeting 400 Gbps and 1 Tbit) based on multi-carrier super-channels supported by intense digital signal processing. We present results on modulation format agnostic polarization demultiplexing, computationally efficient chromatic dispersion equalization, and digital(More)
Random polarization rotations caused by residual fiber birefringence is an important physical effect in optical coherent systems employing polarization-division multiplexing. The specificity of the large penalties induced by polarization-related impairments make polarization-dedicated equalization subsystems mandatory for the design of flexible coherent(More)
In this work, we experimentally implement an adaptive polarization demultiplexing (PolDemux) technique based on the representation of the state of polarization (SOP) of the signal in the Stokes space in bidirectional ultra-dense wavelength-division-multiplexed (U-DWDM) optical metro networks. BER measurement is used to assess the quality of DP-QPSK and(More)
A best fitting plane method and its application for Stokes space based polarization demultiplexing of a PDM-QPSK signal is presented. In particular, we investigate the dynamics of the normal vector to the plane, and the way its orientation depends on the step-size parameter of the method, among other parameters. It is also analysed how the performance of(More)
Digital signal processing (DSP) is nowadays a key enabling technology in coherent optical transmission systems, triggering an increasing research effort on the development and optimization of DSP subsystems. The first DSP development step is often based on the use of simulation tools and offline processing of experimental data. Complementarily, real-time(More)
We demonstrate an hardware implementation of nonlinear equalization algorithms, numerically assessed using a polarization-multiplexed 16 quadrature amplitude modulation (PM-16QAM) transmission system. Nonlinear equalization is based on split-step Fourier (SSF) method and on a simplified Volterra series nonlinear equalizer (simVSNE). Hardware implementation(More)
We review recently proposed nonlinear mitigation methods based on a frequency-domain Volterra series expansion for high-speed and long-haul optical transmission systems. Using a symmetric kernel reconstruction we derive a set of parallel frequency-domain filters that constructively add up to rebuild the matrix-based Volterra series nonlinear equalizer(More)
A sliding window method to apply the Stokes space based polarization multiplexing technique in a time varying SOP scenario is proposed. The method uses the Stokes space representation of the signal samples SOP in order to dynamically reverse the coupling between the two orthogonal polarizations. We show that the variables of the method, the number of(More)