Spectrally efficient enhanced-performance bidirectional coherent PON with laserless 10 Gb/s ONU [invited]
TL;DR: In this article, a bidirectional, ultradense wavelength-division multiplexing passive optical network (PON) was proposed for video overlay over 30 km standard single-mode fiber.
Abstract: We present and experimentally characterize a spectrally efficient, bidirectional, ultradense wavelength-division multiplexing passive optical network (PON) (2 × 120 Gb/s at 50 GHz) over 30 km standard single-mode fiber. This is achieved using a 4 GHz grid with partial spectrum overlapping, Nyquist-shaped 16-ary quadrature amplitude modulation, and digital frequency shifting. This scheme is based on a laserless, self-homodyne PON with centralized wavelength control. We achieve reduced impact of the Rayleigh back-scattering effect due to Nyquist-pulse shaping and frequency upshifting. Self-homodyne detection relaxes the laser linewidth requirement and digital signal processing complexity at the optical network unit. To demonstrate the extra benefit of the proposed PON system, we also experimentally and theoretically evaluate the impact of nonlinear Raman crosstalk in video overlay. Compared to a baseband Nyquist signal and baud rate non-return-to-zero equivalent, the proposed system improves the carrier-to-Raman crosstalk ratio of video overlay by 4 and 6 dB, respectively.
Citations
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TL;DR: In this paper, the progress in ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON) is reviewed by making use of the key attributes of this technology in the context of optical access and metro networks.
27 citations
Patent•
13 Feb 2016TL;DR: In this article, a phase-correlated, orthogonally-polarized, light-stream generator (POLG) was presented for preparing light into phase coherent light streams having defined states of polarization and spectral composition.
Abstract: In one aspect, the present disclosure relates to a communications system which, in one embodiment, includes a phase-correlated, orthogonally-polarized, light-stream generator (POLG) for preparing light into phase coherent light streams having defined states of polarization and spectral composition. In one embodiment, the POLG includes a light source configured to emit light having a predetermined wavelength and a polarization apparatus configured to prepare light from the light source into particular states of polarization. The POLG also includes a phase modulator configured to produce light having a plurality of wavelengths and configured to retard the phase of propagation of light with a first state of linear polarization while not retarding the phase of light with a state of linear polarization orthogonal to the first state of linear polarization when an external electric field is applied. The POLG also includes an electrical oscillator configured to periodically apply an electric field to the phase modulator.
11 citations
TL;DR: In this paper, a cost-effective ultradense wavelength division multiplexed (UDWDM) passive optical network (PON) which uses phase modulation (PM) of the optical carriers in the optical line terminal (OLT) in order to achieve inherent noise immunity in the network is proposed and analyzed.
Abstract: Abstract In this paper, we have proposed and analyzed a novel cost-effective ultradense wavelength division multiplexed (UDWDM) passive optical network (PON) which uses phase modulation (PM) of the optical carriers in the optical line terminal (OLT) in order to achieve inherent noise immunity in the network. In the demodulation of the optical PM signal at the optical network unit (ONU), we have proposed to use a simple injection–locked Fabry–Perot (FP) laser diode (LD) for achieving PM to intensity modulation (IM) converter which is followed by a photodiode to recover the specific channel information. A detailed analysis of PM–IM conversion in an injection–locked FPLD has been carried out and the viability of the proposed scheme has been established. The proposed UDWDM–PON which is a broadband access network is cost-effective and long reach.
5 citations
TL;DR: By reusing the downstream optical signal as the upstream optical carrier, the proposed R-Co-PON enhances the optical spectral efficiency and confirms the potential applicability of the proposed system in future optical access networks, particularly those using wavelength-division multiplexing.
4 citations
TL;DR: The proposed self-homodyne detection at optical network unit (ONU) requires neither frequency offset compensation nor phase noise compensation, and thus can significantly reduce system complexity and power consumption.
4 citations
References
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TL;DR: General OFDM principles, including orthogonality, cyclic prefix use, frequency-domain equalization, and multiuser OFDMA are summarized, followed by an overview of various optical OFDM(A) transceiver architectures for next-generation PON.
Abstract: In this tutorial overview, the principles, advantages, challenges, and practical requirements of optical orthogonal frequency division multiplexing (OFDM)-based optical access are presented, with an emphasis on orthogonal frequency division multiple access (OFDMA) for application in next-generation passive optical networks (PON). General OFDM principles, including orthogonality, cyclic prefix use, frequency-domain equalization, and multiuser OFDMA are summarized, followed by an overview of various optical OFDM(A) transceiver architectures for next-generation PON. Functional requirements are outlined for high-speed digital signal processors (DSP) and data converters in OFDMA-PON. A techno-economic outlook for such a “software-defined,” DSP-based optical access platform is also provided.
511 citations
"Spectrally efficient enhanced-perfo..." refers background in this paper
...…exponential growth of bandwidth-consuming In-ternet services such as cloud computing and online video streaming is fueling the development of wavelength-division multiplexing passive optical networks (WDM-PONs) with a dedicated 10 Gb/s per user in nextgeneration heterogeneous access networks [1]....
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TL;DR: The role of forward error correction has become of critical importance in fiber optic communications, as backbone networks increase in speed to 40 and 100 Gb/s, particularly as poor optical-signal-to-noise environments are encountered.
Abstract: The role of forward error correction has become of critical importance in fiber optic communications, as backbone networks increase in speed to 40 and 100 Gb/s, particularly as poor optical-signal-to-noise environments are encountered. Such environments become more commonplace in higher-speed environments, as more optical amplifiers are deployed in networks. Many generations of FEC have been implemented, including block codes and concatenated codes. Developers now have options to consider hard-decision and soft-decision codes. This article describes the advantages of each type in particular transmission environments.
421 citations
TL;DR: New technologies that facilitate multiple access beyond 10 Gb/s time division multiple access (TDMA)-PONs will be reviewed, with particular focus on the motivation, key technologies, and deployment challenges.
Abstract: This paper reviews the future directions of next generation passive optical networks. A discussion on standardized 10 Gb/s passive optical network (PON) systems is first presented. Next, new technologies that facilitate multiple access beyond 10 Gb/s time division multiple access (TDMA)-PONs will be reviewed, with particular focus on the motivation, key technologies, and deployment challenges. The wavelength division multiplexed (WDM) PON will be discussed and in combination with TDMA, the hybrid WDM/TDMA PON will be reviewed in the context of improving system reach, capacity, and user count. Next, discussions on complementary high-speed technologies that provide improved tolerance to system impairments, capacity, and spectral efficiency will be presented. These technologies include digital coherent detection, orthogonal frequency division multiple access (OFDMA), and optical code division multiple access (OCDMA).
361 citations
"Spectrally efficient enhanced-perfo..." refers background in this paper
...…he exponential growth of bandwidth-consuming In-ternet services such as cloud computing and online video streaming is fueling the development of wavelength-division multiplexing passive optical networks (WDM-PONs) with a dedicated 10 Gb/s per user in nextgeneration heterogeneous access networks…...
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01 Oct 1999
TL;DR: In this article, the dependence of the crosstalk on subcarrier frequency, wavelength spacing, and optical power is measured and analyzed in a two-wavelength 1550-nm standard fiber system at sub-carrier frequencies 50-800 MHz.
Abstract: Crosstalk in a two-wavelength 1550-nm standard fiber system at subcarrier frequencies 50-800 MHz is investigated. The dependence of the crosstalk on subcarrier frequency, wavelength spacing, and optical power is measured and analyzed. The observed crosstalk is attributed to three primary mechanisms: stimulated Raman scattering, cross-phase modulation, and the optical Kerr effect combined with polarization-dependent loss. At wavelength spacing greater than 9 nm, stimulated Raman scattering dominates. At wavelength spacing less than 5 nm, the primary contributor can be the optical Kerr effect with polarization dependent loss, except at higher modulation frequencies where cross-phase modulation also is significant. At even modest (by CATV standards) optical power, the crosstalk is as high as -40 to -45 dB.
137 citations
"Spectrally efficient enhanced-perfo..." refers background in this paper
...1943-0620/15/03A403-11$15.00/0 © 2015 Optical Society of America use self-homodyne detection (SHD) and signal-frequency upshifting from DC [17,18]....
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TL;DR: In this article, the authors describe the capabilities, design and implementation of a coherent ultra dense WDM technology for optical metro and access networks, which enables variable downstream bit rates from 150 Mbit/s up to 10 Gbps per user, embedded OTDR and the coexistence with legacy systems such as GPON, EPON, XGPON or RF-Video.
Abstract: Coherent optical communication has been well established as the technology of choice for long haul and high bit rate communication systems since a decade ago. Recent technology advances and ongoing price erosion further open the window of opportunity for the application of coherent optical transmission technology in other domains. This paper describes in detail the capabilities, design and implementation of a coherent ultra dense WDM technology for optical metro and access networks. Its capabilities enable a number of attractive options, such as variable downstream bit rates from 150 Mbit/s up to 10 Gbit/s per user, embedded OTDR and the coexistence with legacy systems such as GPON, EPON, XGPON or RF-Video in optical distribution networks. Due to its flexibility and capacity, it is also suitable for deployments in metropolitan networks, as well as for mobile front-haul and back-haul applications.
109 citations
"Spectrally efficient enhanced-perfo..." refers background in this paper
...One option is a single high-bandwidth front-end generating/processing unit using one wavelength, one modulator, and one receiver that requires high electrical bandwidth devices on the transmitter and receiver sides [8]....
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...Coherent ultradense wavelength-division multiplexing (UDWDM) together with multilevel modulation formats enables high wavelength count with high aggregated capacity and easier network upgrade for flexible bandwidth PONs [8–11]....
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