| 1. |
- Iglesias Olmedo, Miguel, et al.
(författare)
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Digital signal processing approaches for semiconductor phase noise tolerant coherent transmission systems
- 2015
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Ingår i: Optical Metro Networks and Short-Haul Systems VII. - : SPIE. - 9781628414783
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Konferensbidrag (refereegranskat)abstract
- We discuss about digital signal processing approaches that can enable coherent links based on semiconductor lasers. A state-of-the art analysis on different carrier-phase recovery (CPR) techniques is presented. We show that these techniques are based on the assumption of lorentzian linewidth, which does not hold for monolithically integrated semiconductor lasers. We investigate the impact of such lineshape on both 3 and 20 dB linewidth and experimentally conduct a systematic study for 56-GBaud DP-QPSK and 28-GBaud DP-16QAM systems using a decision directed phase look loop algorithm. We show how carrier induced frequency noise has no impact on linewidth but a significant impact on system performance; which rises the question on whether 3-dB linewidth should be used as performance estimator for semiconductor lasers.
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| 2. |
- Iglesias Olmedo, Miguel, et al.
(författare)
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Gigabit Access Passive Optical Network Using Wavelength Division Multiplexing-GigaWaM
- 2014
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 32:22
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Tidskriftsartikel (refereegranskat)abstract
- This paper summarizes the research and technical achievements done under the EU project GigaWaM. The goal of this project was to develop a cost-effective solution that can meet the increasing bandwidth demands in access networks. The approach was to use a novel wavelength division multiplexing passive optical network (WDM-PON) architecture that can deliver symmetric 1 Gb/s to 64 users over 20 km standard single mode fiber using the L and C bands for down and upstream, respectively. During the course of the project, a number of key enabling technologies were developed including tunable transceivers, athermal 50 GHz spaced arrayed waveguide grating multiplexer devices, novel hybridization technologies for integration of passive and active electro-optic devices, and system-level algorithms that ensure the quality of service. The outcome of the project proved a reliable, cost-effective, flexible, and upgradable WDM-PON solution, achieving per-user datarates of 2.5 and 10 Gb/s for up and downstream, respectively. The proposed solution is not only suitable for access networks, but also for metro aggregation and mobile backhaul.
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| 3. |
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| 4. |
- Iglesias Olmedo, Miguel, 1987-
(författare)
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Impairment Mitigation in High Capacity and Cost-efficient Optical Data Links
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work presented in this thesis fits within the broader area of fiber optics communications. This is an important area of research as it provides a breeding ground for the present and future technologies supporting the Internet. Due to the ever-increasing bandwidth demands worldwide, the network infrastructures that make up the Internet are continuously being upgraded. This thesis aims to identify key segments of the Internet that are deemed to become the Internet's bottleneck if new technology does not replace the current one. These are datacenter intra and inter-connects, and metropolitan core area networks. In each category, we provide a comprehensive overview of the state of the art, identify key impairments affecting data transmission, and suggest solutions to overcome them. For datacenter intra and inter-connects, the key impairments are lack of bandwidth from electro-optic devices, and dispersion. Solutions attempting to tackle these impairments must be constrained by cost and power consumption. The provided solution is MultiCAP, an alternative advanced modulation format that is more tolerable to dispersion and provides bandwidth management features, while being flexible enough to sacrifice performance in order to gain simplicity. MultiCAP was the first advanced modulation format to achieve over 100~Gb/s in 2013 for a data-center interconnect and set the world record on data transmission over a single VCSEL in 2014 for a short reach data link. On metro-core networks, the challenge is to efficiently mitigate carrier induced frequency noise generated by modern semiconductor lasers. We point out that, when such lasers are employed, the commonly used laser linewidth fails to estimate system performance, and we propose an alternative figure of merit we name "Effective Linewidth". We derive this figure of merit analytically, explore it by numerical simulations and experimentally validate our results by transmitting a 28~Gbaud DP-16QAM over an optical link.
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| 5. |
- Iglesias Olmedo, Miguel, et al.
(författare)
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Multiband Carrierless Amplitude Phase Modulation for High Capacity Optical Data Links
- 2014
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 32:4, s. 798-804
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Tidskriftsartikel (refereegranskat)abstract
- Short range optical data links are experiencing bandwidth limitations making it very challenging to cope with the growing data transmission capacity demands. Parallel optics appears as a valid short-term solution. It is, however, not a viable solution in the long-term because of its complex optical packaging. Therefore, increasing effort is now put into the possibility of exploiting higher order modulation formats with increased spectral efficiency and reduced optical transceiver complexity. As these type of links are based on intensity modulation and direct detection, modulation formats relying on optical coherent detection can not be straight forwardly employed. As an alternative and more viable solution, this paper proposes the use of carrierless amplitude phase (CAP) in a novel multiband approach (MultiCAP) that achieves record spectral efficiency, increases tolerance towards dispersion and bandwidth limitations, and reduces the complexity of the transceiver. We report on numerical simulations and experimental demonstrations with capacity beyond 100 Gb/s transmission using a single externally modulated laser. In addition, an extensive comparison with conventional CAP is also provided. The reported experiment uses MultiCAP to achieve 102.4 Gb/s transmission, corresponding to a data payload of 95.2 Gb/s error free transmission by using a 7% forward error correction code. The signal is successfully recovered after 15 km of standard single mode fiber in a system limited by a 3 dB bandwidth of 14GHz.
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| 6. |
- Iglesias Olmedo, Miguel, et al.
(författare)
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Towards 100 Gbps over 100m MMF using a 850nm VCSEL
- 2014
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Ingår i: Optical Fiber Communication Conference, OFC 2014. - Washington, D.C. : Optical Society of America. - 9781557529930
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Konferensbidrag (refereegranskat)abstract
- Employing MultiCAP signaling, successful 70.4 Gbps transmission over 100m of OM3 MMF using off-the-shelf 850 nm VCSEL with 10.1 GHz 3-dB bandwidth is experimentally demonstrated indicating the feasibility of achieving 100 Gbps with a single 25 GHz VCSEL.
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| 7. |
- Kakkar, Aditya, et al.
(författare)
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Design of coherent optical systems impaired by EEPN
- 2016
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Ingår i: 2016 Optical Fiber Communications Conference and Exhibition, OFC 2016. - Washington, D.C. : Institute of Electrical and Electronics Engineers (IEEE). - 9781943580071
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Konferensbidrag (refereegranskat)abstract
- We present experimental validation of novel analytical expressions essential for the design of coherent optical systems impaired by EEPN. These expressions enable a simple and accurate EEPN analysis for any system specification.
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| 8. |
- Kakkar, Aditya, et al.
(författare)
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Design of coherent optical systems impaired by EEPN
- 2016
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Ingår i: 2016 Optical Fiber Communications Conference and Exhibition (OFC 2016). - 9781943580071
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Konferensbidrag (refereegranskat)abstract
- We present experimental validation of novel analytical expressions essential for the design of coherent optical systems impaired by EEPN. These expressions enable a simple and accurate EEPN analysis for any system specification.
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| 9. |
- Kakkar, Aditya, et al.
(författare)
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Overcoming EEPN in Coherent Transmission Systems
- 2016
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Ingår i: 2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO). - Washington, D.C. : IEEE conference proceedings. - 9781943580118
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Konferensbidrag (refereegranskat)abstract
- We for the first time experimentally demonstrate a simple technique to overcome EEPN. Performance recovery from above FEC to <1 dB penalty for 28 Gbd 16-QAM over 520 km with high LO linewidth is achieved.
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| 10. |
- Navarro, Jaime Rodrigo, et al.
(författare)
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Carrier Phase Recovery Algorithms for Coherent Optical Circular mQAM Systems
- 2016
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 34:11, s. 2717-2723
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Tidskriftsartikel (refereegranskat)abstract
- The phase noise tolerance of circular multilevel quadrature amplitude modulation (C-mQAM) constellations employing different carrier phase recovery (CPR) algorithms is studied. A differential decoding scheme and a bit mapping for this type of constellations are proposed. A novel CPR scheme for C-mQAM constellations is also presented. The particular distribution of the constellation points in a C-mQAM signal is exploited to reduce the required Nth power for the removal of the modulation component by a factor of two. Hence, the computational complexity of the proposed algorithm is drastically reduced. The combined linewidth symbol duration product (Delta nu T-s) tolerance of different CPR algorithms for C-mQAM constellations is studied and compared with the proposed CPR scheme. The results are analyzed at 3.8e-3 and 1e-2 bit error rate forward error correction limits. The proposed CPR scheme achieves similar Delta nu Ts tolerance compared to single stage BPS algorithm while its computational complexity is reduced by group factors of 27.2 vertical bar 32.3, and 30.5 vertical bar 32.6 (in the form of multipliers vertical bar adders) for C-16QAM and C-64QAM, respectively.
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| 11. |
- Navarro, Jaime Rodrigo, et al.
(författare)
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Phase noise tolerant carrier recovery scheme for 28 Gbaud circular 16QAM
- 2015
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Ingår i: European Conference on Optical Communication, ECOC. - : Institute of Electrical and Electronics Engineers (IEEE). - 9788460817413
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Konferensbidrag (refereegranskat)abstract
- We propose a novel carrier phase recovery scheme for circular 16QAM coherent transmission systems. Experimental results show low penalties (<1.4 dB) even for linewidths where square 16QAM exhibits irretrievable (above the FEC limit) error floor.
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| 12. |
- Navarro, Jaime Rodrigo, et al.
(författare)
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Two-Stage n-PSK Partitioning Carrier Phase Recovery Scheme for Circular mQAM Coherent Optical Systems
- 2016
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Ingår i: Photonics. - : MDPI AG. - 2304-6732. ; 3:2
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Tidskriftsartikel (refereegranskat)abstract
- A novel two-stage n-PSK partitioning carrier phase recovery (CPR) scheme for circular multilevel quadrature amplitude modulation (C-mQAM) constellations is presented. The first stage of the algorithm provides an initial rough estimation of the received constellation, which is utilized in the second stage for CPR. The performance of the proposed algorithm is studied through extensive simulations at the forward error correction bit error rate targets of 3.8 x 10(-3) and 1 x 10(-2) and is compared with different CPR algorithms. A significant improvement in the combined linewidth symbol duration product (Delta vT(s)) tolerance is achieved compared to the single-stage n-PSK partitioning scheme. Superior performance in the Delta vT(s) tolerance compared to the blind phase search algorithm is also reported. The relative improvements with respect to other CPR schemes are also validated experimentally for a 28-Gbaud C-16QAM back-to-back transmission system. The computational complexity of the proposed CPR scheme is studied, and reduction factors of 24.5 broken vertical bar 30.1 and 59.1 broken vertical bar 63.3 are achieved for C-16QAM and C-64QAM, respectively, compared to single-stage BPS in the form of multipliers broken vertical bar adders.
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| 13. |
- Olmedo, Miguel Iglesias, et al.
(författare)
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Carrier recovery techniques for semiconductor laser frequency noise for 28 Gbd DP-16QAM
- 2015
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Ingår i: Optical Fiber Communication Conference, OFC 2015. - Washington, D.C. : IEEE. - 9781557529374
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Konferensbidrag (refereegranskat)abstract
- We report on the first experimental comparison of DD-PLL, two-stage feed forward, and two variations of extended Kalman filtering for tracking semiconductor laser frequency noise. We identify which carrier phase recovery technique works best depending on the carrier induced frequency noise profile.
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| 14. |
- Olmedo, Miguel Iglesias, et al.
(författare)
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Chirp investigation in EMLs towards frequency shift keying modulation
- 2014
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Ingår i: Asia Communications and Photonics Conference 2014. - Washington, D.C. : OSA.
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Konferensbidrag (refereegranskat)abstract
- This paper presents a chirp modeling and experimental results that support our vision of enabling frequency shift keying (FSK) exploiting the chirp effect in externally modulated lasers (EMLs).
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| 15. |
- Olmedo, Miguel Iglesias, et al.
(författare)
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Effective Linewidth of Semiconductor Lasers for Coherent Optical Data Links
- 2016
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Ingår i: Photonics. - : MDPI AG. - 2304-6732. ; 3:2
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Tidskriftsartikel (refereegranskat)abstract
- We discuss the implications of using monolithically integrated semiconductor lasers in high capacity optical coherent links suitable for metro applications, where the integration capabilities of semiconductor lasers make them an attractive candidate to reduce transceiver cost. By investigating semiconductor laser frequency noise profiles we show that carrier induced frequency noise plays an important role in system performance. We point out that, when such lasers are employed, the commonly used laser linewidth fails to estimate systemperformance, and we propose an alternative figure of merit that we name "Effective Linewidth". We derive this figure of merit analytically, explore it by numerical simulations and experimentally validate our results by transmitting a 28 Gbaud DP-16QAM over an optical link. Our investigations cover the use of semiconductor lasers both in the transmitter side and as a local oscillator at the receiver. The obtained results show that our proposed "effective linewidth" is easy to measure and accounts for frequency noise more accurately, and hence the penalties associated to phase noise in the received signal.
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| 16. |
- Ozolins, Oskars, et al.
(författare)
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100 GHz EML for high speed optical interconnect applications
- 2016
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Ingår i: European Conference on Optical Communication (ECOC). - : Institute of Electrical and Electronics Engineers Inc.. - 9783800742745 ; , s. 127-129
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Konferensbidrag (refereegranskat)abstract
- We report on a 116 Gbit/s OOK, 4PAM and 105 Gbit/s 8PAM optical transmitter using InP-based integrated EML for interconnect applications with up to 30 dB static extinction ratio and over 100 GHz 3 dB bandwidth with 2 dB ripple.
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| 17. |
- Ozolins, Oskars, et al.
(författare)
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100 GHz Externally Modulated Laser for Optical Interconnects
- 2017
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 35:6, s. 1174-1179
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Tidskriftsartikel (refereegranskat)abstract
- We report on a 116 Gb/s on-off keying (OOK), four pulse amplitude modulation (PAM) and 105-Gb/s 8-PAM optical transmitter using an InP-based integrated and packaged externally modulated laser for high-speed optical interconnects with up to 30 dB static extinction ratio and over 100-GHz 3-dB bandwidth with 2 dB ripple. In addition, we study the tradeoff between power penalty and equalizer length to foresee transmission distances with standard single mode fiber.
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| 18. |
- Ozolins, Oskars, et al.
(författare)
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High-speed optical and wireless transmission-challenges and achievements
- 2016
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Ingår i: Advances in Wireless and Optical Communications (RTUWO), 2016. - : IEEE. - 9781509015368 - 9781509015351
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Konferensbidrag (refereegranskat)abstract
- The cloud services together with the huge size datasets are driving demand for bandwidth in datacenters. The 400 Gbps client-side links are demanding a solution. The intensity modulation and direct-detection systems together with integrated semiconductor lasers and modulators appear as promising solution in four optical lanes at 100 Gbps net rate in order to reduce complexity, size, power consumption and cost.
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| 19. |
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| 20. |
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| 21. |
- Piels, Molly, et al.
(författare)
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Laser Rate Equation-Based Filtering for Carrier Recovery in Characterization and Communication
- 2015
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 33:15, s. 3271-3279
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Tidskriftsartikel (refereegranskat)abstract
- We formulate a semiconductor laser rate equation-based approach to carrier recovery in a Bayesian filtering framework. Filter stability and the effect of model inaccuracies (unknown or unuseable rate equation coefficients) are discussed. Two potential application areas are explored: Laser characterization and carrier recovery in coherent communication. Two rate equation-based Bayesian filters, the particle filter and extended Kalman filter, are used in conjunction with a coherent receiver to measure frequency noise spectrum of a photonic crystal cavity laser with less than 20 nW of fiber-coupled output power. The extended Kalman filter is also used to recover a 28-GBd DP-16 QAM signal where a decision-directed phase-locked loop fails.
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| 22. |
- Piels, M., et al.
(författare)
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Rate equation-based phase recovery for semiconductor laser coherent transmitters
- 2015
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Ingår i: Optical Fiber Communication Conference, OFC 2015. - Washington, D.C. : OSA - The Optical Society. - 9781557529374
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Konferensbidrag (refereegranskat)abstract
- We present a novel carrier recovery technique for coherent systems with semiconductor lasers that incorporates the laser dynamics. A sensitivity improvement of 8dB over a decisiondirected phase-locked loop is achieved experimentally for 28GBd DP-16QAM.
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| 23. |
- Tatarczak, A., et al.
(författare)
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Enabling 4-Lane Based 400 G Client-Side Transmission Links with MultiCAP Modulation
- 2015
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Ingår i: Advances in Optical Technologies. - : Hindawi Publishing Corporation. - 1687-6393 .- 1687-6407. ; 2015
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Tidskriftsartikel (refereegranskat)abstract
- We propose a uniform solution for a future client-side 400 G Ethernet standard based on MultiCAP advanced modulation format, intensity modulation, and direct detection. It employs 4 local area networks-wavelength division multiplexing (LAN-WDM) lanes in 1300 nm wavelength band and parallel optics links based on vertical cavity surface emitting lasers (VCSELs) in 850 nm wavelength band. Total bit rate of 432 Gbps is transmitted over unamplified 20 km standard single mode fiber link and over 40 km link with semiconductor optical amplifier. 70.4 Gb/s transmission over 100 m of OM3 multimode fiber using off-the-shelf 850 nm VCSEL with 10.1 GHz 3 dB bandwidth is demonstrated indicating the feasibility of achieving 100 Gb/s per lane with a single 25 GHz VCSEL. In this review paper we introduce and present in one place the benefits of MultiCAP as versatile scheme for use in a number of client-side scenarios: short range, long range, and extended range.
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