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IEEE Photonics Technology Letters 01/2012; 24(15):1328-1330. · 2.19 Impact Factor
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G Raybon,
A L Adamiecki,
S Randel,
C Schmidt, P J Winzer,
A Konczykowska,
F Jorge,
J Dupuy,
L L Buhl,
S Chandrasekhar,
others
IEEE Photonics Technology Letters 01/2012; 24(15):1328-1330. · 2.19 Impact Factor
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ABSTRACT: We present a new class of optical modulation formats based on the combination of m-ary pulse-position modulation (m-PPM) or m-ary frequency-shift keying (FSK) with additional polarization and/or phase modulation, which is applied on the information carrying pulses in the case of m-PPM or on the information carrying frequency carriers in the case of m-FSK. We describe the principle and implementation of this class of optical modulation formats, and formulate their theoretical receiver sensitivities in optically pre-amplified receivers. Pilot-assisted frequency-domain equalization, similar to that used in coherent optical orthogonal frequency-division multiplexing (CO-OFDM), is used for reliable channel estimation and compensation. CO-OFDM also allows m-FSK to be implemented with high spectral efficiency. As a particular format in this class, m-PPM in combination with polarization-division-multiplexed quadrature phase-shift keying (PDM-QPSK), termed as PQ-mPPM, offers superior receiver sensitivity in optically pre-amplified receivers at bit error ratios (BERs) around the thresholds of common forward-error correction codes. Record receiver sensitivities of 3.5 photons per bit (ppb) at BER = 10(-3) and 2.7 ppb at BER = 1.5 × 10(-2) are experimentally demonstrated at 2.5 Gb/s and 6.23 Gb/s using PQ-16PPM and PQ-4PPM, respectively. We further demonstrate the transmission of a 6.23-Gb/s PQ-4PPM signal over a 370-km unrepeatered ultra-large-area-fiber span with 71.7-dB total loss budget.
Optics Express 12/2011; 19(26):B868-81. · 3.59 Impact Factor
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G. Raybon, P.J. Winzer,
A.A. Adamiecki,
A.H. Gnauck,
A. Konczykowska,
F. Jorge,
J.-Y. Dupuy,
L.L. Buhl,
C.R. Doerr,
R. Delbue,
P.J. Pupalaikis
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ABSTRACT: A single-polarization 160-Gb/s (80-Gbaud) electronically time-division-multiplexed (ETDM) quadrature phase-shift-keyed (QPSK) signal is generated and coherently detected using two 45-GHz-bandwidth oscilloscope prototypes and offline processing.
IEEE Photonics Technology Letters 12/2011; · 2.19 Impact Factor
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ABSTRACT: Multicarrier Offset-QAM is proposed as a spectrally efficient scheme for highspeed coherent optical communication systems. Low penalties are found with symbol-rate spacing in a back-to-back experiment. The scheme can be implemented with low complexity.
Optical Communication (ECOC), 2011 37th European Conference and Exhibition on; 10/2011
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R. Ryf,
A. Sierra,
R.-J. Essiambre,
A.H. Gnauck,
S. Randel,
M. Esmaeelpour,
S. Mumtaz, P.J. Winzer,
R. Delbue,
P. Pupalaikis,
A. Sureka,
T. Hayashi,
T. Taru,
T. Sasaki
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ABSTRACT: We experimentally demonstrate transmission of 6 mode-multiplexed 20-Gbd-QPSK signals over 1200 km of three-core microstructured fiber (3C-MSF). An aggregate single-wavelength capacity of 240 Gbit/s is recovered by off-line 6×6 coherent multiple-input multiple-output (MIMO) digital signal processing.
Optical Communication (ECOC), 2011 37th European Conference and Exhibition on; 10/2011
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C.R. Doerr,
L. Zhang, P.J. Winzer,
N. Weimann,
V. Houtsma,
T. Hu,
N.J. Sauer,
L.L. Buhl,
D.T. Neilson,
S. Chandrasekhar,
Y.K. Chen
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ABSTRACT: We realized a monolithic dual-polarization dual-quadrature coherent receiver with balanced detection on InP using a single epitaxial step. It monolithically integrates the polarization splitters, 90° hybrids, and balanced photodiodes in 4.1 mm<sup>2</sup> . We demonstrate reception of 112-Gb/s polarization-division-multiplexed quadrature phase-shift keying with 17.3-dB optical signal-to-noise ratio at 10<sup>-3</sup> bit-error rate.
IEEE Photonics Technology Letters 07/2011; · 2.19 Impact Factor
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ABSTRACT: This issue aims at providing a diverse coverage of the current state of research in digital optical communication technologies, ranging all the way from deep-space laser communications to terrestrial fiber-optic transport, packet, and access networks to digital optical communications for computer interconnects and on-chip integration.
IEEE Journal of Selected Topics in Quantum Electronics 11/2010; · 3.78 Impact Factor
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ABSTRACT: We demonstrate ten-channel wavelength-division-multiplexed (WDM) transmission of 56-Gbaud polarization-division-multiplexed quadrature phase-shift keying signals (i.e., at a line rate of 224 Gb/s) over 1890 km of fiber on a 100-GHz WDM grid (spectral efficiency of ~2 b/s/Hz). The coherent intradyne receiver digitizes the signal at 80 GSamples/s, and is followed by offline digital signal processing.
IEEE Photonics Technology Letters 08/2010; · 2.19 Impact Factor
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ABSTRACT: We apply information theory to optical fibers in the context of transmitting information in optical networks. We define a ¿fiber channel¿ suitable for such networks and present fiber capacity estimates for transmission over 500 km. We compare our capacity estimates to recent record capacity experiments.
Information Sciences and Systems (CISS), 2010 44th Annual Conference on; 04/2010
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ABSTRACT: We describe a method to estimate the capacity limit of fiber-optic communication systems (or ¿fiber channels¿) based on information theory. This paper is divided into two parts. Part 1 reviews fundamental concepts of digital communications and information theory. We treat digitization and modulation followed by information theory for channels both without and with memory. We provide explicit relationships between the commonly used signal-to-noise ratio and the optical signal-to-noise ratio. We further evaluate the performance of modulation constellations such as quadrature-amplitude modulation, combinations of amplitude-shift keying and phase-shift keying, exotic constellations, and concentric rings for an additive white Gaussian noise channel using coherent detection. Part 2 is devoted specifically to the "fiber channel.'' We review the physical phenomena present in transmission over optical fiber networks, including sources of noise, the need for optical filtering in optically-routed networks, and, most critically, the presence of fiber Kerr nonlinearity. We describe various transmission scenarios and impairment mitigation techniques, and define a fiber channel deemed to be the most relevant for communication over optically-routed networks. We proceed to evaluate a capacity limit estimate for this fiber channel using ring constellations. Several scenarios are considered, including uniform and optimized ring constellations, different fiber dispersion maps, and varying transmission distances. We further present evidences that point to the physical origin of the fiber capacity limitations and provide a comparison of recent record experiments with our capacity limit estimation.
Journal of Lightwave Technology 03/2010; · 2.78 Impact Factor
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ABSTRACT: We discuss the generation, wavelength-division-multiplexed (WDM) long-haul transmission, and coherent detection of 112-Gb/s polarization-division-multiplexed (PDM) 16-ary quadrature amplitude modulation (16-QAM) at a line rate of 14 Gbaud and spectral efficiencies beyond 4 b/s/Hz. We describe the (off-line) digital signal processing and blind filter adaptation algorithms used in our intradyne receiver and characterize its performance using both simulated and measured 16-QAM waveforms. We measure a required optical signal-to-noise ratio of 20.2 dB (0.1-nm reference bandwidth; 10<sup>-3</sup> bit-error ratio), 3.2-dB off the theoretical limit. We study the effects of finite analog-to-digital converter resolution, laser frequency offset, laser phase noise, and narrowband optical filtering. Our experiments on a 25-GHz WDM grid (4.1-b/s/Hz spectral efficiency) reveal a 1-dB penalty after 7 passes though reconfigurable optical add/drop multiplexers (ROADMs) and an achievable transmission reach of 1022 km of uncompensated standard single-mode fiber. At a spectral efficiency of 6.2 b/s/Hz (16.67-GHz WDM channel spacing) a transmission reach of 630 km is attained.
Journal of Lightwave Technology 03/2010; · 2.78 Impact Factor
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ABSTRACT: In this letter, we calculate theoretical limits to fiber-optic transport capacity under the constraint of requiring the use of concentric multiring modulation alphabets. Subject to these conditions, we vary ring amplitude ratios and occupation probabilities to determine the capacity-optimized ring constellations. The technique used for fiber transmission calculations accurately captures all fiber nonlinear effects, with the accuracy limited by the noise and signal statistical properties only.
IEEE Photonics Technology Letters 11/2009; · 2.19 Impact Factor
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ABSTRACT: Time-dependent inter-packet and intra-packet BER variations are implemented in the ns-2 network simulator to evaluate fast packet protection based on physical-layer monitoring through pre-FEC BER read-out.
Optical Communication, 2009. ECOC '09. 35th European Conference on; 10/2009
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ABSTRACT: A 56-Gbaud (224-Gb/s line rate) polarization-division multiplexed quadrature phase shift keyed (PDM-QPSK) signal is transmitted over 2,500 km (32 × 80 km) of fiber and is coherently detected using two 80-GSamples/s oscilloscopes with off-line signal processing.
Optical Communication, 2009. ECOC '09. 35th European Conference on; 10/2009
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G. Wellbrock,
T.J. Xia,
W. Lee,
G. Lyons,
P. Hofmann,
T. Fisk,
B. Basch,
W. Kluge,
J. Gatewood, P.J. Winzer,
G. Raybon,
H. Song,
A. Adamiecki,
S. Corteselli,
A.H. Gnauck,
D.A. Fishman,
T. Kawanishi,
K. Higuma,
Y. Painchaud
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ABSTRACT: A 107-Gbps field trial carrying live HDTV traffic over a 504-km in-service DWDM route, proving commercial systems designed for 10G/40G can be upgraded to 100G without impacting existing active channels.
IEEE Lasers and Electro-Optics Society, 2008. LEOS 2008. 21st Annual Meeting of the; 12/2008
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ABSTRACT: We demonstrate intradyne detection of 112-Gb/s 16-QAM (14-Gbaud, polarization-multiplexed) in a 10-channel WDM environment on a 25-GHz grid. We show the robustness of a central channel to multiple add/drop filtering and transmission over 315 km.
Optical Communication, 2008. ECOC 2008. 34th European Conference on; 10/2008
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ABSTRACT: We discuss the impact of amplification technologies, multi-level constellations and fiber nonlinearity on the spectral efficiency achievable in fiber-optic networks.
IEEE/LEOS Summer Topical Meetings, 2008 Digest of the; 08/2008
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ABSTRACT: We study the statistics of transmission impairments due to polarization-mode dispersion in systems characterized by the hinge model. In particular, we validate the use of a computationally efficient expression for the probability density function (PDF) of the differential group delay (DGD) of systems with an arbitrary number of hinges. We then combine this expression for the PDF of the DGD with the outage map approach to compute outage probabilities and noncompliant capacity ratios for transmission links with varying numbers of sections (from 4 up to 20), each for several values of mean DGD and different system parameters.
Journal of Lightwave Technology 08/2008; 26(14):2110-2117. · 2.78 Impact Factor
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ABSTRACT: We explain why maximum-likelihood sequence estimation (MLSE) receivers for direct-detection optical communication systems do not achieve the single-pulse performance of threshold receivers, in which there is no intersymbol interference (ISI). For this purpose, we propose a simple and intuitive model to approximate the performance of MLSE receivers under the assumption of moderate ISI. A performance analysis of this model shows that an MLSE receiver does not reach the performance of an ISI-free threshold receiver. By simulations we evaluate the range over which the model accurately approximates the MLSE receiver.
IEEE Photonics Technology Letters 05/2008; · 2.19 Impact Factor
