The emergence of capable semiconductor processes has allowed digital signal processing to extend the application range high-capacity optical systems. We report performance polarization multiplexed (or dual-polarization) quadrature phase-shift keying at 40 and 100 Gb/s.

We examine analog-to-digital and digital-to-analog converters (ADCs DACs), as well digital signal processing (DSP) functions for optical coherent modems.

In this paper, we discuss building blocks that enable the exploitation of optical capacities beyond 100 Gb/s. Optical networks will benefit from more flexibility and agility in their network elements, especially coherent transceivers. To achieve 400 Gb/s more, transceivers operate at higher symbol rates. This be made possible with bandwidth components using new electro-optic technologies implemented indium phosphide silicon photonics. Digital signal processing algorithms. Multi-dimensional...

The demand for increased bandwidth is ever present. Coherent technology coupled with advanced modulation formats and digital signal processing a key enabler optical communication systems at 100 Gb/s beyond. This article reviews the attributes of coherent in light challenges faced by system designers to realize bit rates next-generation systems.

Perturbation based nonlinearity pre-compensation has been performed for a 128 Gbit/s single-carrier dual-polarization 16-ary quadrature-amplitude-modulation (DP 16-QAM) signal. Without any performance degradation, complexity reduction factor of 6.8 demonstrated transmission distance 3600 km by combining symmetric electronic dispersion compensation and root-raised-cosine pulse shaping with roll-off 0.1. Transmission over 4200 standard single-mode fiber EDFA amplification was achieved the DP...

Operators are pressured to maximize the achieved capacity over deployed links. This can be obtained by operating in weakly nonlinear regime, requiring a precise understanding of transmission conditions. Ideally, optical transponders should capable estimating regime operation from received signal and feeding that information upper management layers optimize characteristics; however, this estimation is challenging. paper addresses problem linear signal-to-noise ratio (SNR) signal. performed...

We report the longest unregenerated reach achieved for a 10 Gb/s return-to-zero differential phase shift keying (RZ-DPSK) system on standard dispersion fiber (G652) with no optical compensation.

For excellent cost and performance, modern high capacity transport systems use digital coherent processing to overcome many physical barriers. Coherent methods are explained measured performances shown for commercial at 100 Gb/s beyond.

Toward reduced-complexity digital implementation, frequency domain Volterra-based nonlinear equalization (VNLE) structures for multistep fiber nonlinearity compensation are proposed. In the cascade structures, is performed before (cascade-1) or after (cascade-2) dispersion in each step. Superior performance with shorter discrete Fourier transform (DFT) lengths and fewer steps compared to conventional VNLE parallel structure demonstrated a transmission experiment. The experimental results...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We report the measured wavelength-division-multiplexing (WDM) performance and polarization-mode dispersion (PMD) tolerance of a coherent 40-Gbit/s dual-polarization quadrature phase shift keying (DP-QPSK) transceiver at 50-GHz minimum channel spacing in 40-channel 40-span test bed comprised 3200 km uncompensated G.652 fiber. also evaluate impact polarization-dependent loss (PDL) on system present...

The introduction of coherent transceivers in high capacity optical transmission systems has dramatically increased networking capabilities. We discuss how enhancing flexibility these enables dynamic optimization DWDM signal characteristics to extract more from networks.

For high symbol rate fiber optic networks, the estimation and monitoring of time varying link performance parameters are critical for delivering optimal network performance. In this paper, a method is presented estimating nonlinear signal-to-noise ratio (SNR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nl</sub> ) using an artificial neural (ANN). The ANN trained with nonlinearity induced amplitude noise covariance phase correlation extracted...

A new family of Nyquist pulses for coherent optical single carrier systems is introduced and shown to increase the nonlinearity tolerance dual-polarization (DP)-QPSK DP-16-QAM systems. Numerical investigations a single-channel 28 Gbaud long-haul system without dispersion compensation indicate that proposed pulse can reach distance by 26% 19%, roll-off factors 1 2, respectively. In multi-channel transmissions factor 1, 20% reported. Experimental results DP-QPSK at 10 confirm superior pulse.

Dominated by IP traffic Total is projected to exceed 100 exabyte/mo 2016 (1 exabyte = 1018 bytes) 1 ~ 10 Tb/s of installed capacity (using factor 3.3 peak/avg traffic) ~20% 30% year over growth 500 new per might be required 2025 total global 2011 (WARNING: extrapolations may misleading)

An artificial neural network model to estimate fiber nonlinear noise-to-signal ratio based on amplitude noise covariance of received symbols is proposed. Standard deviation 0.2 dB obtained in simulation, and estimation error <;0.6 verified experiment.

Traditionally, optical fiber nonlinearity is considered a limiting factor for transmission systems. Nevertheless, from system design perspective this can be exploited to minimize the impact of uncertainty on performance. A consequence that it becomes beneficial consider at stage, resulting in probabilistic design, rather than conventional approaches whereby added by way margins deterministic design. In paper, we conduct extensive experimental measurements quantify multispan wavelength...

Frequency multiplication of a microwave signal was achieved by modulating one arm dual-wavelength distibuted-feedback (DPB) laser device and injection locking the other on modulation sidebands. The consists two DFB lasers integrated with Y-junction combiner same semiconductor substrate, thus making compact (L=500 /spl mu/m). output allowed to beat high-speed photodetector. resulting had narrow line shape superimposed Lorentzian pedestal at multiple radio frequency. Three regimes operation...

We report the longest unregenerated reach achieved for a 10-Gb/s return-to-zero differential phase-shift keying system on standard dispersion fiber (G.652) with no optical compensation. A total of 82.433 ns/nm chromatic compensation was achieved.

We present 18 months of field observations on the state-of-polarization (SOP) and polarization-mode dispersion (PMD) three routes monitored using deployed coherent 40 Gb/s transponders. Two fiber paths were each different routes, ranging from 30 km with one amplified span to 273 seven spans. In general, changes in SOP PMD slow, autocorrelation half-width-half-maxima 1.3 4.1 days for differential-group-delay 0.18 1.7 SOP. observed largest correlation active periods between sharing same cable...

An intersymbol-interference-free pulse shape is specifically designed for self-phase-modulation (SPM) mitigation. It experimentally shown to increase the SPM tolerance of a 40-Gb/s single-channel postcompensated dual-polarization quadrature phase-shift keying system by 1.5 dB. Numerical analyses at 40 and 100 Gb/s indicate that specialized can maximum reach G.652 fiber G.655 up 1190 820 km, respectively.

This paper presents novel techniques to measure the total and longitudinal nonlinear phase shifts, as well net dispersion with a dual-polarization digital coherent transceiver in multi-span fiber optic system. We show, additional information of span lengths core effective areas, that launched power profile can be estimated. The measurement is based on cross-phase modulation between two orthogonally polarized subcarriers acting pump probe, which are generated from same transmitter. With...

Hybrid OFDM-digital filter multiple access (OFDM-DFMA) PONs exploit software configurable digital shaping filters in ONUs to multiplex gapless OFDM channels at different radio frequencies and utilize a single FFT operation-based pipelined DSP procedure the OLT simultaneously de-multiplex/demodulate all signals from various without requiring any matching filters. In this letter, aggregated raw 30Gbit/s over 25km multipointto-point upstream signal transmissions of IMDD OFDM-DFMA are...